Dear Dr Holick, i am reading your book actually and somewhere, i don,t know if it,s here on the web or in the book, i think i read that patients suffering, i think chimio is worse than illness, suffering chimio will recover much better if they take vit D3. This morning i was very sad to hear that a good friend is beginning chimio tomorrow because they,ve found he has colorectal cancer. I am not sure if he can read english, so in case he can,t, is there any advise i could give him? I can,t find in your table measures for ill people. He is a male, not fat, strong, 50 years old. We are from Spain seams we don,t get enough sun either I would be really thankful if you could answer to me, you see he is a brave and honest man, has a 7 year old daughter, his work is about risking his life to keep us all safe. Thanks a lot, Esther

Hi, Thank you very much for your answer. I have a combined vit D2 and vit D3 score of 19. My doctor has prescribed 2,500 IU per day. In preference I am taking Solgar's vitamin D3 of 4000 IU per day in tablet form. Is this enough to raise it quickly? Also, can you get vitamin D being made in the body if you expose your skin on cloudy days? I'm 52. Best foods? Enormous;ly grateful for advice. Best wishes, Karina

My doctor recommended I supplement vitamin D last year in addition to magnesium. I have always taken Cod Liver Oil/Butter Oil, but added 2000 at first and then maybe more than 5000 mg. of D per day; I also took 300 mg. of magnesium daily. I also eat eggs and salmon frequently, and lots of vegetables. Get very little sun and am very fair. My D level went from 23.9 to 52.1. Magnesium went from 3.8 to 2.9. So, I'm upset - I fear the low magnesium is due to overdoing the D. I also took K2. My doctor wasn't bothered by the D level, and just told me to supplement magnesium, as if I weren't already doing that. In addition, my sodium was slightly low. Any suggestions for me? I am already stopping all vitamin D supplementation, but continuing with magnesium. I feel I should have followed my earlier instincts. Thanks for any help you can give me, with the understanding that you are not able to treat or diagnose by email. Sincerely, Debbie

My daughter was diagnosed with chronic pain amplification syndrome 3 years ago, just this week they have checked her vitamin d level for the first time. The results came back at 17.9. My daughter lives in chronic pain and can not live her life to the full. I was told by my doctor this week this deficency could be the cause of all her pain in her body, do you think this is the case? I would really appreciate your help, have you studied or seen any evidence of this? Thank you so much in advance Helen Megson

Hello Doctor, Good day and I hope all is well. I'm a mom and I'm 38 years old, my question is that I did a blood test to check the vitamin D and the results showed that I need to take medication since it is 36 which is under the normal, and the doctor told me to start taking oravil (one dose every two weeks for 3 months and then one dose every month). is that enough?? Thank you, Jenny

Hello Dr. I did run a blood test for Vitamin D and it was 11, so I started to take the "Ci-Cal D125", but I also have a deficiency in "Hematocrit" are they related to my deficiency in Vitamin D? many thanks

the doctor gave it to me, it is some sort of supplement , this is the picture of it

Thank you for your reply, I am taking a pill once every day and the doctor told me I should take it for 4 months, but I was wondering if this deficiency is in somehow related to my anemia? Or there’s no connection between anemia and Vitamin D, Many thanks Dr. J

I just finished Dr. Holick's Vitamin D book and noted a couple of things: 1) Other practitioners have mentioned that Vitamin K2 is important to take with Vitamin D and 2) Vitamins are unregulated as to strength, with the exception of USP-labelled products. There is no mention of either of these things in your book. I enjoyed reading and learning about Vitamin D!

Hi Dr Holick I loved your book but there is something that i want to make sure i get right You wrote a paper on vitamin D3 and said that that half-life of D3 is 2 weeks. So that would men that D3 is out of the body in 4 weeks (2x half-life) So lets say my weight was 200 lbs and i was aiming for 35 units of D3 per lbs of bodyweight, which would mean that i would have to take 7,000 IU of D3 If i took 10,000 IU on Saturday would that mean thath i would have 7,500 IU in my blood by the end of the week ? Half life is 2 weeks so 50% loss in 2 weeks but 25% lost in 1 week 10,000 IU - 25% = 7,500 IU If i have understood this then why do people tell people that they must take D3 every day ? is it all a scam by the drug companies to milk us? I would love to read your answer, and again your book was life changing !

which are the best hours to have a sunbath to produce more vit D?

Dear Dr. Holick, Congratulations for your work, I have both your books, further recommended them and personally used them in my work. For the first time I met a person (female, age 38) who has 25-OH-vit D at a level of 185ng/mL, without having ever supplemented. What could be the possible cause of hipervitaminosis in this case? Warm Regards and Thank You for Your Time, Cristela GEORGESCU

Doctor Holick. I am a 45yo male and have been trying to supplement D3 in order to recover from a level of 17ng/ml. Doses above 1000iu (which by all accounts is not enough to recover with) a day make me urinate every hour or more and experience severe insomnia. Even the lower doses do irritate my urination a bit just not as severely. Do you have any recommendations?

Dr. Holick - I am a Registered Dietitian and have studied many of your research articles. I also had the pleasure of attending a presentation you gave at Michigan State University while I was attending dietetics school there. Recently, I was found to be vitamin D deficient with a blood level at 11 ng/mL of 25-hydroxy vitamin D, total. My PCP prescribed 50000 IU vitamin D2 weekly for 6 weeks. I am a fair female that wears sunblock when in the sun, and as you know we don't get much in the midwest! However, I have a diet full of the staples of vitamin D: salmon, tuna, milk, yogurt, fortified breakfast bars, mushrooms, eggs, swiss cheese, so, I was surprised to see how low my vitamin D was. I had my vitamin D re-tested after 4 weeks of taking the supplement since I was going to be traveling somewhere warm and sunny for vacation prior to finishing the supplement and wanted to determine if the level was coming up prior to sun exposure. My blood level increased to 22 ng/mL, technically wnl, but I would like to see it > 30 as your research suggests is optimal. My PCP sent a letter indicating my level was now 'normal' and would like me to take a maintenance dose of 2000 IU vitamin D daily. I have read research that suggests a connection to calcification of soft tissues and vessels with calcium and vitamin D supplementation and am concerned about taking a long-term daily supplement. I am wondering if you know of a connection with vitamin D supplement only and calcification or any adverse effects. I have looked into the Sperti vitamin D lamp you reference in your 2007 NEJM Review article "Vitamin D Deficiency." Would you suggest the Sperti lamp as a safer option to a daily oral supplement? Thank you for your time and expert advice, Elizabeth

Thank you so much for your reply. Can I please ask you if they have given my daughter the right amount 20,000 one per week? As I said before my daughter has suffered with chronic pain for 4 years and has got a level of 17.9 do you think that her level could have been low for all this time? I'm just concerned that there is something else going on too with her having pain for such a long time. Also is 17.9 low as when I look on the Internet for answers there are lot of different answers. Thank you once again Helen Megson Sent from my iPhone

I have had an ileostomy for 10 years, due to Ulcerative Colitis. Recently, my levels of Vitamin D have been diagnosed to be extremely low (5), despite taking one injection and supplements for the past 4 months or so. It seems like I am not absorbing it either through the supplements or the injection. What would you suggest? Is this normal with ileostomists?

Dear Dr. Holick, I have been browsing the web about sun exposure and health and I found the term "Sensible sun exposure". I realized that this is what I am already doing, furthermore, I have taken it to a whole new level whith a handheld device that displays the current UV index in real time. Last summer I had 10-15 minute daily sun exposures with skin type 2 in swimming shorts. The UV index was between 4.0 and 7.5. In may my D3 level was 16 ng/ml and in september it was 26.4 ng/ml. This summer I am aiming for a higher D3 level, therefore longer exposure times. Additionally I am logging each session with date, UV index, exposure time and amount of skin exposed. I can give you the data at the end of this summer. I am looking forward to your answer! Best regards, Zoltan

I have read your book and use the sun azimuth website and go out for 20-30 min when the sun is 50 degrees in the sky in just a bathing suit. I am having an opposite reaction to vitamin D supplements and Sun exposure. I get a mild depression and irritability instead of an uplifted mood. It feels exactly the same from supplements as it does from the sun. I do not have depression normally, do you have any idea why this might be happening. I continue to get sun exposure despite the adverse mood because I feel it important to raise my vitamin D levels. I was at 19 last season when I started and raised to 32. I wonder if it has any connection to my thyroid hormones?

Dr. Holick, I came across a YouTube of your Vitamin D talk with the University of California and found in immensely helpful. I had recently tested deficient in Vitamin D (22 ng/ml) and began supplementing with both sun exposure and oral intake of D3. I'm currently taking 10,000 IU daily in an attempt to quickly get my levels up to your recommended range (30yo male), and plan to throttle down to a maintenance dose of 5,000 IU once I reach desired levels. My question is regarding vitamin K2, and whether it is necessary for safely taking Vitamin D3 orally. I was warned by my physician that taking D3 without K2 could calcify my arteries and lead to cardio vascular disease? Is this a valid concern, and if so how much K2 would you recommend ingesting daily. I hope to hear from your and thank you in advance for your guidance, -Dario Traverso

im 23 yrs ols and im on vitamin d3 solutions twice weekly. my vitamin d level is 5 what do i do?

Dear Dr Holick, since you have a life time experience and research on vitamin D ,and you have the DRI'S and RDA of vitamin D ,when we are doing research and supplementing patients to get optimal levels of vitamin D ,and we supplement them with 50,000 iu wkly and and follow them for six months and once the level is raised we put them on a maintenance dose of 50,000 iu once a month and second need info on one alpha hydroxylase and the eliza kit has the reference range of .2-66 ng/ml what does this indicate and how to interpret the results of deficient and sufficient patients .sorry i forgot to introduce myself my name is Bushra and im doing research on vit def associated with mammographic density and epithelial cell proliferation .

Where do you buy the acitve vitamin cream for psoriasis. thank you

Respected Prof Hollick, I am a PhD student from India and i am working on T2DM and vit D levels in kashmir valley where we recieve less sunlight.I have found a corelation between them.Can you guide me in my topic that will be of your kindness

Dear Dr Holick I live in Australia, and I have had raised ALP for the last year ( 149) upper normal range is 115. My Vitamin D levels are 80. I have no liver disease, but am concerned I may have Pagets - am due to have a bone X Ray. Can I ask what are your thoughts re these levels and Vit D deficiency being a possible cause? Thankyou Dr Holick, Regards, Kathy

Good morning Dr. Holick, I am a multiple sclerosis patient and do the treatment with vitamin D 3 years and a half, using the protocol Dr. Cicero Galli Coimbra. In 2013 I was in the Vitamin D symposium, I have given you a thank-folder. In Brazil many people do supplementation 10,000 ui, however this very common claim that Vitamin D this dose needs to be combined with vitamin k2 for calcium to be redimencionado properly, avoid to go to the soft tecideos, the doctor who recommends that statement in Brazil is Dr. Lair Ribeiro in the US Dr.Joseph Mercola I've read your book and I do not remember this association with vitamin k2, I wonder if it is really necessary to take vitamin k2 for people who take 10,000 iu of vitamin D. I am 4 groups moderator on facebook with over 40,000 members and this doubt is very common Thank you very much Ricardo Marques dos Santos

Dear Dr. Folick thankyou for your reply after your email, i took vit D 3.000 iu/day, from only 2x400 iu before in the toe joints feel better, but still stiff in finger joints , especially when I wake up the more I stay active the better it feels how long the impact of the damage caused by lack of vitamin D will improve? is there any food/drink that i should avoid regards, Lystiani

Dear dr. Holick, i am from indonesia which is tropical area but i had my joints and muscles aches, pains, and fatigue. RF=negatif, ANA=negatif, ESR=32, Fe=20 and vit D=6.7. I am 52 and menopause. doctor said I have an autoimune syndrome. Is it enough taken 1x2.000iu vit D to improve my condition ? what else should i take to lower my ESR?

Dr. Holick, I am a caregiver to a 71 year old man that suffers from chronic pain due to shingles 40 years ago. To get out of the pain, his doctor cut his nerves 40 years ago but it did not work, so now he lives with constant debilitating pain. He has been in the bed about 20 hours a day for the past 40 years. I doubt he is in the daylight more than 2 hours a week, and it's never in the sun. How in the world can his vitamin d level be normal? He only just started taking 50,000 iu once a week. His levels are: 25-HYDROXY, D2 <3.0 ng/ml 25-HYDROXY D3 (GROUP) 49.9 ng/ml

Hello Dr. Holick, I was recently diagnosed deficient with a level of 20. Dr. prescribed 50,000 iu D2 once a week but 3 weeks in, changed it to 50,000iu twice a week. I am 5'7 260lb. Is this too much? Is it the wrong form of D? Dr. said that D2 is easier to absorb, and we will switch to D3 after 8 weeks. When asked if I should also take Magnesium, Calcium, and Vitamin K, she said no, those levels were fine. I am worried about the amount of D she has me taking, and that it will cause problems without taking the other supplements. I am not sure if the Dr. is up to date on Vitamin D deficiency, and am not sure I should trust any of the stories from people not educated correctly, Can you help please? I am also hypothyroid, hypertension (norvasc,hypochorothiazide), PCOS. Thank you!!! Rachel Tweedy

My name is Simona, I'm from Romania and I have 32 years. I want to take vitamin D, but I don't know exactly what dose is good for me. My level of 25-OH Vitamin D is 24.2 ng/ml. This is my story: In July 2014 my right side of the face it was numb and I recovered in about a month, but in June 2015 I had another episode in which my left hand and left foot was numb, had weight in both left hand and in the left leg, muscle weakness and coordination disorders left hand, and subsequently left foot. 5 days I did Solu Medrol (methylprednisolone) treatment. After this treatment, in about a month I recovered completely. In April 2016 I repeated brain MRI with contrast material. The conclusion was active demyelinating lesions without character - in progression outnumber compared to 07/07/2015. Please Dr Holick, what dose of vitamin D must take? Thank you very much!

Greetings Dr. Holick, The other day while walking I bumped into a woman who told me she is walking for the first time in many years. She has started the Dr.Coimbra Protocol using vitamin D3 under the guidance of a doctor in Naples, Florida. The lady has MS but she is responding to this treatment! Can you tell me about it, and do you endorse it? Thank you!

By showering right after the recommended time of exposure to the sun, does one lose any of the benefits of the vit D hormone that's created on & in the skin? Thank You for your very valuable research in this field and the ability to lucidly convey your important discoveries & information to the masses.

Dear dr. Holick, i am from indonesia which is tropical area but i had my joints and muscles aches, pains, and fatigue. RF=negatif, ANA=negatif, ESR=32, Fe=20 and vit D=6.7. I am 52 and menopause. doctor said I have an autoimune syndrome. Is it enough taken 1x2.000iu vit D to improve my condition ? what else should i take to lower my ESR?

Thank you for your quick response. You words have given me lot of strength and hope to live with patience . It all started from a sternum pain 7 months back but was diagnosed finally 3 months back after changing my doctor when my symptoms increased gradually. If possible I will write you again after my improvements in another couple of months. Thanks a lot again and god bless. With Warm Regards Nishant

Hello Doctor , Greetings, I would like to consult you regarding my problem related to severe Vitamin D Deficiency and B12 Deficiency. I tested my Blood Serum levels 3 months back Vitamin D:7 ng/ml(normal is 50-100) Vitamin B12: 159 pg/ml(normal is 239 -931) Which says I was sever deficient. After taking Vitamin D Supplements(as prescribed by my GP-60000IU/Week) for 3 months my level was : Vitamin D: 52 ng/ml Vitamin B12: 426 pg/ml Its good to see that levels have improved but symptoms have worsened. I don't know how long Vitamin D Recovery takes but symptoms is not improving. Initially I was having fatigue, weakness, joint and knee pain. From past 20 days its has started Hand Tremors, Hand Tingling and numbness. I really don't know what is happening to me. Specially in morning when I awoke I feel very weak with full body pain. I am 26 year old slightly obese male from India. My Thyroid tests also have came negative. Sir, I came to know about your profile & you great work on Vitamin D from Internet, Can you throw some light on my case or any piece of advice. I am really worried and don't know when I will feel that much energetic I was 4 months back. I will be very grateful if I hear from you. Regards Nishant

Dr. Holick, Your vitamin D presentation on youtube is the best use of powerpoint and humor I have ever seen. I’m an engineer and give presentations to prospective clients that are in the oil and gas industry regarding drilling software. They are technical presentations. I feel like they can be much better after seeing what is possible. Your vitamin D presentation is a scientific topic, but I was glued to the screen for the whole hour. I wanted to ask, do you make your own powerpoints with animations and images? Is there a specific resource or author that has influenced the way you present your material with humor? That’s it. Thank you sir for sharing your experiences and knowledge with us in a lighthearted way. Nikita K.

Dear Dr. Holick, I have a vitamin D deficiency (13 ug/L) and I would like to know if this could be the cause for having joint pain. I practice yoga, and there are several movements that are really painful such as, some lateral movements and when I embrace my knees, feeling hip and groin joint pain. Also, I would like to know if this deficiency could be related with some gluten sensitivity, since I read some studies addressing this possibility. Thank you. Kind regards, Patricia

recommended daily dose in elderly?

If my base level is 20 ng/ ml, And I take 4000 iu per day , My serum level of 25(oh)d, should become 24 or 60 ng /ml, Or else. In an average case, Regards , I am a Pediatrician

Hi Dr. Holick, Yesterday I asked you a question regarding the effects of gluten or more specifically whole grains, on Vit D, and if it lowers your levels of Vit D. This question I presented to you at the New England Public Nurse conference at the Colony Hotel in Kennebunkport, ME. I went back to see where I had read about this and it is in the Paleo Solution, p. 116, where Dr. Cordain notes several studies that have had this conclusion including a 1919 study by Dr. Edward Mellanby of London University as well as Dr. Roberto Chignola at the University of Verona. Is it possible to do a study that address the effects of whole grains on Vit D? And, if so, can I participate as a research aide? I work currently as a RN Case Manager in acute care, I have a Master's in Education. I used to teach at Bunker Hill Community College in Boston as well as Northern Essex and my classes included pathophysiology, nutrition, and A &P to mostly nursing students. I am almost done with my MPH that I will obtain along the way while I continue to pursue my PhD of Public Health through Walden University. I would like to get involved in research but I do not have any particular experience. I could possibly help collect and enter data. Please let me know your thoughts! I really enjoyed your presentation and thank you sharing this vital information with us as it will allow for us to share it with others to help and prevent many preventable diseases. Sincerely, Alana Evans

Good morning, this message has been translated from Italian. In March 2015 ulcerative colitis. Probably thanks to a late diagnosis of my doctor in the past 5 or 6 years I suffered urinary infection, mononucleosis, severe tiredness several episodes of temperatures at 37, 37.1 .... In May the same year starts Coimbra protocol with 30,000 international units vitamin D and then move on to 40,000 in July 2015. CRP and inflammatory bowel index initially high were both normalized going into autumn. During the winter I had a hypertensive crisis with creatinine and glomerular filtered ch up and down until you get to 2In their point masimo amrzo in 2016. I then suspended momentarily vitamna d'm doing antihypertensive therapy and I feel much better as pressure compared to winter. I visited nephrology and as I write I will shortly tac urinary tract with contrast to evaluate (so says nephrologist) renal parenchyma and renal arteries. The same is optimistic about the situation but does not agree very much for the high-dose vitamin d.La my vitamin D is from last exam over 150 safe but I do not know exactly how much because the report only reports the value above this. of course I was always followed by medical "enabled" to the protocol to observe the serum calcium and urinary calcium, and only the second has exceeded the threshold (320) serum calcium levels ever; Furthermore the paratormane approached its lowest value as the rest of you want to get the protocol in order to obtain therapeutic efficacy hoped.It would seem a case of toxicity vit.d but the medical protocol has always told me that there are no problems and to undergo the exams without any problems. I'd love to have an opinion also saw that these things do not often see as not all doctors prescribe such high doses indeed, as you well know. In thanking you I extend cordial greetings.

Dr. Hollick, I hope you can help me out. I am 35 years old and have lived in the sun since I was a tot. My mom and dad were beach people so I grew up on the beach. I also played every outdoor sport imaginable so I would end the summer looking like a piece of mahagony. I have dark brown hair and green eyes. I usually get a slight burn after the winter and moderately to very tan at the end of the summer. I went to a derm for the first time last July and she told me due to my past sun exposure and tanning I was destined for melanoma. I have a ton of tiny moles that you can't see from a few feet away but they are there. Maybe 1mm-3mm's she took three off and two were normal and the other one was the lowest level of atypical. I went to a second derm and he told me my moles looked harmless and I wasn't a high risk for melanoma and I should enjoy my life. He took a mole off my upper thigh that turned out to be a spitz nevus but benign. I am at a loss at what I should do... No one in my family has ever had melanoma my dad worked on roofs his entire life and never wore sunscreen and my mom spent evety second at the beach and in the sun. I love the sun and it makes me feel healthy but need an honest opinion on how high Risk I am

Thank you Doctor Holick, Of those risk factors I have one... A large number of moles. I appreciate people like yourself and the late Dr. Bernard Akerman. In reading about Dr. Akerman he apparently had hundreds of moles and was convinced that sun exposure causing melanoma is not proven. That other factors must be present, bad diet, weakened immune sytem, family history, etc... etc. I have been in a constant state of anxiety since my derm visit last July. I started reading over as much of the medical research as possible and it started calming me down. I also purchased your book and started reading it. I shunned myself from the sun from that visit in July until this April and I felt miserable I even wore SPF 30 on my face during the winter months. For years the whole melanoma epidemic never made sense to me. I grew up on a golf course and beach and befriended hundreds of older golfers and surfers. These guys looked like leather ! The played gold all day or lived on the beach with no suncreeen... just their dark, leathery skin as protection. Some of them had moles all over them. I know they had the non melanoma cancers sliced and cut off them but not one of them got melanoma. I know two people that passed away from melanoma and both of them avoided the sun like the plague. They had fair skin and bright red hair. I decided in April that I wanted to get sensible sun exposure so I downloaded dminder and love the app. I follow the guidelines and have not gotten burnt at all. I do have a very dark tan at the moment but feel confident that this is the bodies healthy reaction to the sun. Can you let me know if I am on the right track in keeping myself healthy and cancer free. I take a green drink loaded with vitamins, minerals and probiotics. I take Vitamin c, Tumeric, Lycopene, Fish Oil, Coconut Oil, Asthaxanthin, and helio care when I plan on being in the sun for the day. Thank you for speaking the truth ! It is reassuring that not everyone is selling their soul for the billion dollar sun screen industry.


I would like to say that this product I recent purchased contains other ingredients such as soybean oil......gelatin.....vegetable glycerin....corn this beneficial for me to take?.....I purchased it on line Puritans's Pride premium super-potency 2000 IU if there is a better vitamin than this...please refer me to it and I will order it.....Thank you Dr. Holick I do get some sun....maybe not enough have a pleasant day

I have a 68 year old male patient diagnosed with primary hyperparathyroidism after a kidney stone. his vitamin D level was slightly low at 26. The patient brought in your book citing a section where you wrote that in patients with primary hyperparathyroidism, starting vitamin D may actually lower calcium and PTH. Have you seen this in your patients, and if so, what would the mechanism for this be, my impression is that vitamin D only increases calcium absorbtion from the intestinal tract, increasing calcium. thanks, Matt Ludemann, MD

Hey Dr. Holick, Really enjoyed reading your book "vitamin d solution." Just wondering if you could comment on caffeine and vitamin d and whether you recommend not drinking coffee to maximize your levels or if it makes no difference? I looked around online and couldn't find any real credible sources with an answer so I thought I'd fire you this question! Thank you so much and keep up the great work/ research! Cheers, Andrew

Thank you for your excellent work on Vitamin D. I live in Melbourne Australia and enjoy the outdoors so I get a fair amount of summer sun. Some years ago, at the end of winter I was feeling a bit flat and tested low in Vitamin D. I think 49 nmol/L so my doctor prescribed 8,000 IU Vit D. Within a few weeks I was feeling much better. Since then I have been taking 50,000 IU Vit D weekly during winter and every second week in summer and none when I have holidays in the sun. Does this sound like reasonable dosing to you?

My Vitamin D level was a 9, so I am very low. My doctor has me on 5000 IU daily. My question is whether I should try to do some exercise while trying to gain Vitamin D or is it better to rest?

Dear Dr. Holick, one of my collegues brought up the question where is the structure in the skin, that is responsible for building 25-hydroxyvitamin D under the influence of UV/sunlight? Most of the references Report only.."in the Skin".... I would be very glad to get your answer. best regards Hans

Good Evening Doctor Holick, My name is donatella barillaro, I'm sorry for my english, but i'm an italian biologist, searching for some information about Solar D. I've just finished to view Your wonderful video about Vitamin D! I appreciate it very very much! I'm vitamin deficient too.... But, i would like to ask You something about Your last article ( i read it but, it was very hard in some steps for my little culture... I don't understand this: -how could You select the UV waves that are responsible for vitamin D production? -Which are the specific waves of UV spectrum which allow vitamin D synthesis? -Did You produce solar D? or this study wants to give a weapon to cosmetic industries to formulate sunscreen like solar D? (i'm a little bit confused, because i don't understand if You are the inventor of solar D, the sunscreen sell in Australia....) -What happen to a sunscreen formula that allows UV irradiation for vitamin D? Do You substitute some filter with other? I'm sorry for my probably so simple or stupid questions..... Thank You so much Dear Doctor Holick! Have a nice day a kind greeting from the south of Italy, donatella

Dear Dr. Holick, My hematologist has told me that, as a patient with Polycythemia Vera, I am at a slightly higher risk than the general population of developing acute leukemia after 15-20 years of having the disease. I have come across some vitamin D research done at the University of San Diego showing that the incidence of leukemia is correlated with latitude and hence sun exposure (i.e. the lower the latitude the lower the chance of developing leukemia). Since all kind of vitamin D research is done these days (some of it of less quality than other), I wanted to ask you what you thought of this particular study and if being vitamin D sufficient can in fact help me ward off the (greater) possibility of developing leukemia at some point in my life. My last 25(OH)D test from last November showed a reading of 90 ng/ml. Regards, Marco

My daughter has Lupus and a major vitamin D deficiency. Because of her Lupus, she can't spend a lot of the time in the sun. The 2,000 IU vitamin D makes her feel unwell. Suggestions?

Do you have any experience treating patients with dietary vitamin D deficiency, low bone density DXA, with initial presentation being spontaneous osteonecrosis of the knee?

Hi Dr. Holick, I am reading your new book with great interest, all my life I have kept out of the sun so I would imagine Vitamin D deficient all of my life the reason for this very fair freckly skin that burn easily Just had a blood test and yes Low vitamin D I am now on 2 drops per day but was wondering about purchasing a Sperti Lamp my only worry is that I had Ovarian cancer stage 1a Agressive cancer in 2012 been clear now 4 years. Always been a healthy person before this just wondering I am safe to use this Lamp? Your advice would be greatly appreciated, I live in the U.K a country with not much sunshine unfortunately
Kindest Regards.

Is there any difference between the two? Is either an appropriate supplement to take? Where can I find published results?

Hi, My name is Anne and I have health issues -- I also have multiple chemical sensitivities and reactions to medications, etc. I have stomach issues with foods and meds... I have read articles and your video on sunshine. One of the few things I can still do is sit in the sunshine -- I live just north of Chicago in Wisconsin most of the year. My doctor said I have a 10 and it is the lowest level she has ever seen -- and that I cannot get Vitamin D from sunshine... that I need to take 50,000 iu 1x a week. I'm hoping you can help with some answers that she could not provide. Will the 10 level of Vitamin D kill me? I don't know how else to say it. I have been in a nursing home (and now home for 7 years) and am relatively home bound. Is there harm to me to try to improve it slowly and safely with foods and sunshine? My health and diet has been the same for the past 8 years and am wondering if it has been a slow slide or does one deplete it quickly? Will something terrible happen if I improve the Vitamin D slower than the 50,000 iu? I appreciate your help and time -- I am in literal tears for the past 10 hours thinking that this Vitamin 10 will cause me to be in a critical or emergency situation shortly -- I don't know anyone who has a lower number to ask. I don't know who to ask for help and you seem very knowledgeable and compassionate. Many, many thanks for your help. Anne

Good morning Dr Holick My adult son & daughter (37 & 39yrs), have recently been diagnosed with an extremely rare genetic condition, Xeroderma Pigmentosum. It is a condition of defective DNA repair, affecting the skin & in some the brain and nervous system (MRI brain scans have shown significant global brain atrophy). Having been extremely sun-sensitive from birth, they have always practiced sun-avoidance using sunscreens & protective clothing. They have now been advised to avoid all UV exposure due to the 1,000 times higher risk of skin cancers. They have also been advised to supplement with 1,000 IU per day of Vitamin D. No treatment is available, as yet, for the neurological aspects. Having read your work, I realise how crucial Vitamin D is for good brain health too and I wonder if you could suggest any further reading material or other resource that might be helpful. I must apologise for contacting you in this way, as I am sure that you are incredibly busy, but we are desperate to find anything that might help to slow the progression of this illness and mainstream medicine does not offer any help at this time. Kindest regards

I am a 53 year old female. I have had symptoms of extreme fatigue for about 8 weeks. My vitamin D level is at 16. I have had a lot of different blood work and ct scan of my abdomen and pelvis. I have also had a bloated feeling and brain fog. My doctors want to keep on testing me rather than say the deficiency is the cause. I am on 50,000 iu of vitamin D per week for about three weeks. I was wondering your feelings about my fatigue, bloat and brain fog? Thank you in advance for any advice you may have!!!

Dr. Holick, has anyone taken a hard look at how closely the D Level estimates from DMinder match actual lab values? I noted last summer the author of the app changed some of his calculations and IU per session seemed to go way down. I really like the app, I think it's cool. I guess I'm just concerned about how accurate it is. Thanks :)

Hi Dr Horlick, what is your position on High Dose Vitamin D therapy and ALS would the method used to treat MS (1000iu/KG) give any benefit, in your opinion. Or should this be considered in line with other medication or diet. Considering ALS is a latitude sensitive condition Many thanks

Dear Dr. Holick, About sixteen months ago my vitamin d level was at 24 ng/dl after taking between 5-10,000 IU vitamin d for several months. While not obese (6'1" and 160 lbs), I do live in the Northeast (Massachusetts) and do not get much sun exposure so I thought I was getting an insufficient dosage or not absorbing well for reasons not clear (I do not have inflammatory bowel disease). My internist could not give much guidance as he felt 24 ng/dl was just fine while I tend to ascribe to the guidelines of the Vitamin D council and Mercola, so was aiming for something more like 50-70 ng/dl. I upped the dose to 20,000 IU. After several more months, my serum levels were still not sufficient, so increased--perhaps not wisely-to 30000 IU. My serum levels were then at 100 ng/dl. Clearly overshot the mark. Still without internist suggestions as to dose range, I then initially cut back to 20,000 IU to see if this had any impact. On retesting, levels were now at about 120 ng/dl which I do not understand and which concerns me in terms to risk--eg., hypercalcemia and its potential negative if not dire consequences. I am going to have a calcium serum level drawn but really do feel the need for some guidance as to how I should approach safely reaching the range of 50-70 ng/dl. Also, a couple of specific questions: should I stop all supplementation at this point? How long will it take for restoration to a good range to be achieved? Any other advice most gratefully appreciated. Thank you for your interest. Edward Emery 16 Armory St. Northampton MA 01060

Hello Dr Holick , I am reading some of your publications in the internet and i want to kindly ask for some second opinion. I am a 30 years old healthy male living in greece. The last two-three years i am facing serious erection problems, cold hands-feet, dry red eyes, frothy urine. I had my thyroid removed back in 2005 but i had no such problems before. Did a ton of rheumatological factors, cardio exams, a ton of urine tests all negative. I searched a lot about my symptoms and i found that i could be vit d deficient. I did blood tests by my self and my vitamin was found really low, only 15 ng/ml despite the sun we get here. My endo told me to take 2200UI pills once per day. The improvement was huge. For a week, i could feel way better, no fatigue and my erections were back again, no red dry eyes, no frothy urine! However, really strange, after the first week the same old symptoms came back again like i never took the supplements... Can you help me in what is going on, or to guide me as what things to troubleshoot please?

Dear Dr. Holick, I am writing to you because of the problems that I suffer for 3 years. In 2012 for the first time appeared digestive problems along with swollen lymph nodes in the abdomen and pain in the navel. Then I was diagnosed with Dyspepsia and I had treatment with Omeprazole medicine which reduced the symptoms until 2015. In 2015, the problems with the stomach reappeared in the form of heaviness in the stomach after eating, slow digestion and pain in the navel and daily bloating. In addition to problems in the stomach, there was a strong cough and then I was diagnosed with asthma. Then Allergic Rhinitis reappeared and I began the treatment of allergy with drug Aerogal. For the first time I was diagnosed with Allergic Rhinitis in 1997. The treatment duration was about 5 years old when symptoms suddenly withdrew. In addition to Dyspepsia, Asthma and Allergic Rhinitis, I often have a lymphadenitis of the neck and armpits. Also, I often have ulcers in the mouth, and I'm not immune to viruses. In the last month, I often have cramps in the calves, and pain in the leg muscles when walking up the stairs or slope. In 2006 I was diagnosed with a rare Pallister-Hall syndrome, Hypothalamic Hamartoma, and Hypopituitarism. I do not take any treatment for this disease. Last year I decided to do on my own initiative test of vitamin D, as my mother has reduced this vitamin and Osteoporosis and Celiac Disease. The result of Vitamin D 25-OH: 27.5nmo / L (reference values 75.0-200.0). For stomach problems I have received therapy Omeprazole, then Nolpaza, and problems still have not disappeared. Every day I have a swollen abdomen and heaviness in the stomach. I decided to explore the Internet diseases that are related to my symptoms and syndrome, and I found connection with deficiency of vitamin D. What do you advise me to do next, which tests to do and whether it needs to be done in your clinic or I can just send you the results?

I've been researching Vit D and it's effects on MS and have found information on Dr. Coimbra in Brazil who gives very high doses of D and has achieved cures for many many people who have MS and other autoimmune diseases. He mentioned in a video on YOUTUBE that taking 10,000 IU/day is not toxic as that is what is gotten from the sun in 20 minutes if you have shorts and a tank top on but I read in other places that as low as 2,000 is what is the safe limit for D. If he is treating an MS patient, he doses with MUCH higher doses and does lab work to adjust the dose and also make sure it's not hurting the patient. My 20 yr. old daughter was just diagnosed w/ MS and will probably have to start Avonex very soon. Looking at their website, it decreases the attacks but one may still have a lot of attacks that can lead to disability and my daughter is only 20 with a long life ahead of her. If there is a better way such as possibly Dr. Coimbra's protocol, I want her to try that. I found there is a doctor in Florida who practices his protocol. I'd even move there if it would help my daughter. My questions for you are is 10,000 IU/day of Vit. D safe? And, do you know of/agree with what Dr. Coimbra is doing? Please answer soon and I very much appreciate your help.

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