Vitamin D Health Benefits

| Modified on Apr 26, 2021

Cofactors Critical to Vitamin D
Posted by Art (California ) on 04/21/2018 920 posts
5 out of 5 stars

Vitamin D and Why it May Not Be Working For You as Well as it Should

Many people take vitamin D because it is noted for many health benefits in hundreds of studies, but for some reason, some people do not seem to be able to obtain benefit from vitamin D. Many people are aware that there are cofactors for vitamin D such as boron, zinc, magnesium, vitamin K-2 and calcium, but we often do not realize how important these cofactors can be in terms of helping vitamin D to be all it can be for our health.

On that note, here is a very brief and easy to read article that clearly and simply explains why magnesium is absolutely needed in order for vitamin D to completely do the job it was meant to do in our bodies.

On a related note, the following very short abstract describes how not enough vitamin D and / or not enough magnesium can potentially create health problems for us!


Posted by Whisperingsage (Northeastern California) on 05/20/2015 47 posts

No, vitamin D is not a mouse poison, warfarin is a mouse poison, also known as coumadin, often used in rehab hospitals, warfarin is known to interfere with vitamin K1 function, Vitamin k1 is the greens vitamin needed for proper functioning of platelets and clotting. Vitamin K1 is converted to vitamin K2 in grass fed milk and meat and eggs, and is valuable for tooth repair and development and skeletal development- and making sure vitamin D works as a team with calcium (along with A, and magnesium) as it guides calcium to bones and ensures proper functions as it pulls it out of soft tissues like arteries and nerves and improper places. K2 prevents heart disease. K2 could safely be used instead of warfarin in knee and hip replacement patients.

Reader Feedback
Posted by Kathi (New Brunswick, NJ) on 04/16/2009

I'm writing to follow up on my vitamin D cure for insomnia report in February. After taking 2000 IU/day for 1.5 months I finally went to my doctor for a Vitamin D blood test, and it was 20 ng/ml, which is considered deficient. I also asked him why he didn't test me for vitamin D last year when I was having incredible trouble sleeping, digesting (I also had IBS) and managing daily life, and was told that insurance would not have paid for the test unless I had a "known" symptom of deficiency such as osteoporosis. However, insurance was very willing to pay for several expensive pharmaceuticals the doctor recommended me to try. A SIMPLE VITAMIN D TEST THEN WOULD HAVE SAVED ME A WHOLE YEAR'S WORTH OF AGONY, AND WOULD HAVE BEEN MUCH CHEAPER FOR ALL CONCERNED. WAKE UP USA WE NEED BETTER PREVENTIVE MEDICINE!!!

I am continuing to do much much better, am now taking 3000 IU/day D3, upping my daily intake of veggies, and also supplementing with ACV/honey, flaxseed oil, 500 mg vit C, and 200-400 mg magnesium citrate (I've read that vit D deficiency can go hand-in-hand with magnesium and potassium deficiency). My "sensitivity" to fish (rich in Vit. D and magnesium) has disappeared! No more IBS! I'm looking forward to some warm sunny spring days when I can get my vitamin D dose from the sun.

EC: Thank you for the update, Kathi!

Pain, Fibromyalgia, Shingles
Posted by Hisjewel (Usa) on 03/29/2018
5 out of 5 stars

I learned so much from that Vitamin D book Robert Henry suggested that I read early 2017.

And I gave the D3 a Purposeful second go because of it. However for some reason I seem to soon forget the necessity of a supplement when I am feeling better.

I went on a vacation and when I returned I had forgotten why I was taking the Vitamin D. All I knew was once again my bones were achy, I started back on the MSM. Then I came across more information that stated that fibromyolgia is a Vitamin D3 deficiency. When I take the 10,000 to 20,000 IU D3 at least 5 days a week, I find it very energizing and when I get up in the morning I automatically stretch. When I don't take it, I do not get that stretch. I am 66 so I guess I need help to stretch.

And also other readings mention that Vitamin D3 taken at a 50,000 IU for 3 days lightens the pains of shingles. And I did try it and after 3 days tested it out by eating a good old peanut butter sandwich, I had no breakout and no pain.


Reader Feedback
Posted by Art (California ) on 09/18/2016 920 posts

Vitamin D is pretty unique to each individual and there is not a one dose fits all application for it. Generally if you carry a lot of body fat it can require significantly more vitamin D to reach a specific 25 OH d serum level than a person who has low body fat even though their weight may be equal. If you are trying to reach a specific 25 OH d level in the optimum range, the only way to do that and be sure is by having a 25 OH d test done. These can be done by mail with a pin prick test directly with a lab. This would be very important if you are trying to treat a specific health issue by getting your 25 OH d level into the upper end of the reference range (reference range: 30 ~ 100 ng/ml).

Some cancer studies suggest that optimal anti-cancer activity may occur around the 80 ng/ml level. Dr. Cannell suggests working your serum level up toward the upper end of the range for autism and even above if improvement continues, and then decrease the dose when no further improvement is seen, but again that would require regular testing by your doctor.

Some people just require more vitamin d than others to reach a specific serum level so it is more important to take whatever dose is needed to reach the desired serum level and test to be sure rather than choose a dose that may or may not achieve the proper 25 OH d serum level for you.


General Feedback
Posted by Valerie (New Zealand) on 10/28/2017

Calcification in tissue occurs in vitamin D deficiency. If you don't get enough, calcium is pulled from bone and the blood levels are high anyway. Taking vitamin D in sensible doses prevents this. It's the people posting about the higher doses and claiming calcium is high that really get me. Yes mega doses over long periods are dangerous. But the RDI is beyond a joke and causing many diseases. For one, if you get calcification Of arteries in deficiency then take doses to address that deficiency, stands to reason that calcium in arteries will be pulled out and put back into bone. And to do this it needs to be in the blood first. Would be handy to know what levels of blood calcium are TOO high, but I would say that when its dissolved from the artery walls with optimal doses, it goes into the blood to be cleared out and has a snowflakes chance in hell if actually adhering to much tissue thereafter. Even the kidneys would be shoving that stuff out. I doubt it could stick to ureters or kidneys any more than it could an artery. Heck calcium levels would have to be dangerously high or way above normal levels.

Dr. Cannell's Vitamin D Newsletter
Posted by Wendy (London, England) on 03/31/2016

I'm surprised by the article which says cod liver oil is poison.

My husband had severe back pain to the point where he could hardly walk when he was around 30. He read at the time that cod liver oil would be beneficial so he started to take a dessertspoon full each day and within 3 months the pain was gone. He was some twenty or so years later, diagnosed with Ankylosing Spondylitis through a problem with he eye which caused the back pain.

I won't say he never had another twinge but I could count on one hand the times this has happened. He has continued with the cod liver oil everyday of his life since and he is now 72 years of age.

I too take a capsule as I couldn't take it off the spoon. I am 68 and thank God I also can still get around without any arthritis.

I will take the point of Vit A interfering with Vit D as I personally have problems with chronic coughing and are upping my dose of Vit D to 4,000 IU per day and haven't been doing it long but have noticed a difference.

Multiple Cures
Posted by John (Nyc, Ny) on 01/15/2010
5 out of 5 stars

I have been in the healing profession (practitioner, researcher, advocate) for 30 years, nothing comes close to my experience with MSM, I am so sorry it took this long to try it. My chronic asthma gone in 3 days!! On albuterol for almost 40 years. I am in shock. Some side effects which I consider to be cleansing symptoms. Nausea, sleeplessness and skin breakouts, but I did start on a high dose of 20 grams a day. After three weeks no more 'side effects'. My energy has greatly increased, I feel quite euphoric every day now. The only time I had that kind of euphoria was by drinking three glasses of organic green juices a day. I think people on heavy medications, mercury fillings, toxic diet are going to have more difficulties with it, so building up from a small dose with extra vitamin C and plenty of pure water will help.

The other supplement that really helps is Vitamin D3, I take 16,000iu liquid daily, no colds for two years now and my chronic bronchitis of 20 years has disappeared. Some years it was mild others, severe triggering serious asthma attacks. So the combination of Vitamin and MSM has been miraculous for me. This great website encouraged me to try MSM. Thanks so much.

p.s. Brushing my teeth with MSM has whitened them.

Posted by Hound (California) on 04/01/2017
5 out of 5 stars

I had a wart on my thumb. It was on the joint which made removing it difficult. Tried for years to get rid of it using compound w and sacylic acid. When I started taking 10,000 IU per day of Vitamin D3 after discovering I was deficient on a serum D blood test, the wart disappeared and never returned.

Reader Feedback
Posted by Valerie (New Zealand ) on 10/28/2017

For the most part, most people are suffering D deficiency because of lack of sunlight actually. Hyperactive Parathyroid is due to boron deficiency from my reading. I'd say that most people out there know if they have not been out in the sun enough when considering the whole vitamin D issue and instinctively know they need it. Scaring people with your personal experiences (rare disease) is just not helpful

Posted by Umbolava (Chicago, IL) on 06/24/2010
5 out of 5 stars

I use apple cider vinegar for my hypertension. I love trader Joes but also have used braggs. I can honestly say I have drank over the past 3 years a more than a hundred bottles. I buy at least 10 to 12 bottles from trader joes at over two dollars a bottle not that expensive. Apple cider vingar works with my blood pressure I had a bp of 200/120 apple cider vinegar just one dose dropped it down to 170/100 still extremely high. Now I am 6 foot 3 280 lbs and need to loose weight bad. I still take apple cider vinegar 4 tablespoonfuls once a day. I should do it a least twice but I don't and probably add some raw garlic. As I am athletic run two miles swim a mile and play sports. I am overly stress work the night shift and around obese people.

However vitamin d has worked better for me than apple cider vinegar. I take 5000 iu daily with magnesium 400mg and One a day vitamin for men. Vitamin D helps my immune system hypertension and regulates my insulin all at the same time. This vitamin D 3 works. Please check out Most americans do not get enough vitamin d because we are always in doors. It is really cheap at whole foods trader joes walmart even dollar general. Please Please add vitamin d3 to your daily routine you will feel and see the difference.

Multiple Cures
Posted by Deirdre (Atlanta, GA) on 02/15/2010

I had the good fortune a couple of weeks ago when I was visiting Los Angeles to speak with an osteopathic doctor from Colorado who has treated and cured many of his patients with D3. The gist of what he told me (sorry, I didn't have any writing instruments with me at the time of the conversation so this is in my memory bank) was that many ailments are healed with vitamin D3 after 2-3 months on the hormone (he refers to it as a hormone, not a supplement). He suggested that I first get my D levels checked at a doctor's office. Once I know the baseline, I can start taking 8,000 iu of vitamin D3 a day. After 3 months, I should get the levels checked again. In summertime some people would be able to drop this daily dose to about 4,000 iu/day or less, but you won't know unless you get your levels checked. He told me people will be very surprised to see how deficient they are in D. Even those that live in sunny climates like Los Angeles are surprisingly deficient in D3.

One of his patients with erectile dysfunction was cured after a two months on D3. Unfortunately, the patient was so thrilled with the results that he started taking a lot more than what was recommended! A blood test showed his D levels soared too high and he had to come off it for about two months. After two months he was deficient again. Interesting, no?

The good doctor also told me that 90% of his patients suffering from migraines were cured after being 2-3 months on D3. The key is give it 3 months at 8,000/day dosage. He recommended the vitamin d council website for further research:

I went to Costco today and was pleased to see part of an aisle covered with D3 supplements! I bought a big bottle of D3 2,000iu capsules for about $12.00.


Leg Pain
Posted by Kathy (Rusk, TX) on 07/01/2009
5 out of 5 stars

I began having leg pain about 6 months ago. Read an article about the use of Vitamin D3 have been taking 2 1000 IU per day and no leg pain.

Cough, Psoriasis
Posted by Debbie (South Bend, IN) on 02/17/2009
5 out of 5 stars

In reference to the cough...I have a friend here at work, age 58 who had been suffering from a bacterial respiratory infection since April of 2008. We work of different floors and I hadn't seen her in a while until she stopped into my office in the middle of January (Tues 1/13) of this year. She was still very, very ill. Whenever she tried to talk she would cough. It was bad. I suggested she do the Vitamin D3 treatment....50,000 ius on the first day followed by 10,000 ius each day for a week and then 50,000 more for the following 2 weeks plus the daily 10,000. Guess what. She is cured. She had been on antibiotics and everything imaginable to get rid of this. She was sick for over 8 months. Not only is her respiratory infection gone but she told me that she is no longer depressed and she has a great outlook on life again. Mind you, when I saw Cindy in January her skin was gray and she couldn't talk without coughing. Today looks completely healthy. I just went upstairs on a errand and I saw her in the classroom with students and the teacher she assists and she was laughing and healthy for the first time in almost a year. Vitamin D is an amazing thing.

I have joined Carol Baggerly's grassroots health plan and intend to be a subject of their vitamin D study. You can get information on the D Action program at

and I will post this again

Great links and and terrific informational web site.

Reader Feedback
Posted by Chuck (Atlanta, GA) on 02/07/2009
5 out of 5 stars

For about 20 years, I had a chronic patch of psoriasis over my left eyebrow. I had tried several prescription and OTC creams, but none of them worked. After reading an article about how thousands of people got relief from psoriasis by sunbathing in the Dead Sea area, I remembered how my own psoriasis would practically disappear during the summer months when I sunbathed regularly. That was when I made the connection between sunshine and vitamin D. So, I started taking a daily supplement of 1000iu of vitamin D, which was in addition to the 400iu in my daily multivitamin. In about a week, I was amazed to see the patch of psoriasis had completely disappeared and has never returned. It may not work for everyone, but it sure worked for me!

Leg Pain
Posted by Toni (Maryland) on 11/10/2015
1 out of 5 stars


The doc likely prescribed you synthetic Vitamin D2. You will greater benefit from taking natural Vitamin D3. Study the research. D2 eventually has a negative affect.

Seasonal Affective Disorder
Posted by Jan (Mi) on 10/11/2018

Seasonal Affective Disorder ..SAD

I am totally convinced that I am suffering from SAD. I was wondering if anyone had any suggestions. I'm looking into getting a therapy light and also wondered if anyone had any suggestions on that. I've searched the internet and there are so many. I do supplement with vitamin D, magnesium, b complex and all the rest of the vitamins and minerals. I try to eat healthy most of the time and exercise (although I need to do more). I do miss the sunshine:(

Seasonal Affective Disorder
Posted by Steve (Nv) on 10/11/2018

5HTP and the light therapy will be hugely helpful for SAD.

Seasonal Affective Disorder
Posted by Jan (Mi) on 10/12/2018

Bill, thanks for the suggestions. I will enjoy reading the sites that you included in your post. I do have niacinamide. I'll get right on it. The B complex too. Thanks again for taking the time to help me out. It's really appreciated.

Thanks, Charity. That was a very sweet reply and so appropriate. We are having an extremely dark gloomy day today and I've just tried to keep in mind how very fortunate I am. And yes, the holidays can be an anxious time, but as I've gotten older, I've given up a lot of things I used to do and let the kids do them now. I do know, that after three or four dark days, it really can get to me and throw me into anxiety/panic attacks. My mood starts to go downhill in late October and get better every March. Thanks again for reminding me to smell the flowers.

General Feedback
Posted by Robert Henry (Ten Mile , Tn) on 08/23/2015

HI U KT, , , , , , , , , , , , , ,


The sun rays that produce Vit D best, do so between 10 am and 2 pm and you only need 30 minutes.

Other than Magnesium, Vit D is probably the best supplement you can take. Of course, you must do a quality D-3 and not the synthetic D-2 that Big Pharma makes.

Kit, I love you, but you got to enroll in my reading plan. Read and when you get tired, read some more. Knowledge is what will keep you healthy if you follow what you learn.


Vitamin D Side Effects
Posted by Gemma (Wales) on 08/19/2015
0 out of 5 stars


I took 10,000iu of vitamin D3 plus a k2 supplement for 3 weeks and developed nasty side effects. My joints all started clicking, my knees became painful and my muscles started twitching. I could also feel a weird sensation in my teeth and had lower back pain. A muscle allergy tester diagnosed calcium deposits in all my joints and tendons and recommended phytoplankton 3 times per day and ACV 3 times per day. I have been taking these for 2 weeks and have had slight improvement (I'm not twitching much anymore). I added a magnesium oil yesterday which appears to have helped my back pain.

But my joints still click (everywhere! ) and my tendons are painful. Other people on vitamin d forums have mentioned their joints clicking too. Have you got any suggestions? Should I try the chanca piedra? I'm scared to put any supplements into my body anymore.

Best Wishes.


D3 Overdose Detox Remedies
Posted by Anon (Anon) on 03/17/2013

Hi, Magnesium salt baths would help (epsom salts). Excess d3 causes kidney stones so watch out for this.

General Feedback
Posted by Mary (Shelton, Wn. Usa) on 02/17/2013

Vit. D(3) is not a vitamin but a hormone. There are 4 ways to get vitamin (hormone) d3:

#1 sun, #2 veggies, #3 fish oils like salmon, codliver, sardines #4 made from lanolin, which includes sprays, liquids, lotions, pills and mouse poison.

One must be very careful taking d3 as it stays in the liver for 3 months, causes the blood to thin, and allows the calcium to get into the blood stream causing clogged arteries, calcium to deposit anywhere it wishes. Look it up.

General Feedback
Posted by Robert Henry (Ten Mile, Tn Usa, Tn Usa) on 02/17/2013

MARY, you know not of what you speak. Name me one vegetable that has vitamin D in it except a mushroom. ====ROBERT HENRY=====

Reader Feedback
Posted by Robert (Manhattan, Ny) on 08/20/2012
0 out of 5 stars

I found from repeated use, on and off, that higher doses of Vit D3 (1000 to 3000iu) results in a negative mood state... So instead I try to make an effort of getting around 10 to 15 minutes of summer sun daily.

Another lesson to myself to remember that despite all the positive claims and current hype about a supplement or herb, one must listen to their body first.

Reader Feedback
Posted by Dorothy (Sydney) on 11/24/2017

I got depressed on cod liver oil. Subtle blue feeling. Stopped taking and it went away. I am now taking D3 but with all the required co-factors. Mag, Bs, K, etc. Ok so far.

Reader Feedback
Posted by Bama Lori (Birmingham, Alabama) on 05/17/2012

You must look at your calcium levels; Get these tests or past blood work results: Calcium- Vitamin D and P T H... This is the parathyroid hormone level which controls calcium levels. D is a response of calcium levels!!

Low D is the body's way of protecting itself from heart damage and stroke due to high levels of calcium, it may only be slightly elevated. Taking D will hurt your heart and cause edema when you have eleveated calcium.


PTH (parathyroid hormone) is the control module for calcium, consider it a thermostat for the body, it is a hormone gland behind the thyroid; it is so important you have four redundant glands that all do the same thing, but only one works at a time.

I had the same problem, was found to have high PTH. Causing high calicium and resulting low D. Reg. Docs all tried to make me take D... HUGE MISTAKE, ok... seriously! My D was only 7-11; It is important that you STOP D, you are harming yourself, doctors can be such idiots!

Go to; read all about it. It was a simple fix, high calicium (mine was never that high but 9. 8-10. 8; my D 7-11; my PTH 90-110; I had one benign parathyroid adenoma... They are benign 99 percent of the time; it is not cancer, dont go there in your mind. My sestamibi scans were negative, dont get caught in that... Oh we cant see it so it doesnt exist, these glands are the size of a grain of RICE ok... Trust no one except the Norman Parathyroid center to get it right if you have high Cal, even a little; or borderline, high PTH and low D... Those three tests alone are enough to diagnose the ademoma without even seeing the bugger!

Have the surgery only the M I R P, minimally invasive, ( I had to go to Tampa and see Dr. Norman, as all others told me it was cancer and it ALL HAD to be removed, including my thyroid and part of the trachea... WRONG... With a very invasive surgery and a life dependant on drugs to survive... NOT THE CASE AT ALL: its outpatient, it takes half a day, and its done. Thyroid nodules were benign as well! They were causing me to be hypothyroid!

The disease is called Bones, STones, Moans, and Groans; If you have achy joints, (I never had stones) been told you have osteporsis developing or osteopenia, high BP , high Cholesterol; GI problems;... Then get this sucker removed; Symptoms of chronic malabsorbtion; all; and changing your diet is the only way to stop these diseases from progressing and developing tumors!

Now, for the cause of this I have finally arrived at FRUCTOSE MALABSORTION; and GLUTEN intol; I have gone gluten free and LOW FODMAP (eliminating foods with high fructose amounts, this includes sugar free additivies, wheat, onions, garlic, apples, honey, HFCS; etc.. With my foods,

the adenoma is a symptom of chronic malabsorbiton, (wiki that) you must find your intolerences and avoid those foods, this is the only cure, I say again, the only cure! Avoidance... Just like a bee allergy, you must not get stung by foods you cannot process, endocrine disease is the result!

- The same swelling a bee sting causes externally is what is happening in your gut (small intestine) and the villi become damaged, cannot uptake minerals from foods, vitamins will NEVER cure this, in fact they will make you sicker!

Sincerely, all my best, Lori PS: Remember medications have fillers, binders and colors that can make all symptoms worse, they did for me everytime. Avoid All colors and dyes, check personal care products, for wheat germ oil; sorbitol; mannitol, etc.

Try going low lactose; real butter hard cheeses only, lactose free milk, no yogurts; no soft cheeses at all; go gluten free; avoid all wheat products (go to for symptoms and lists of unsafe ingrediets, like MSG, INULIN, modified food startch, etc; Low fodmap foods , avoid apples, pears, cabbage family, some types of beans, no pasta, no breads. (LOW FODMAP) Seek out Shephard works and Wiki on Fructose Malabsorbtion, up to 30 percent of caucasians have it, especially euro decent!

Reader Feedback
Posted by Robert Henry (Ten Mile, Tn Usa) on 12/25/2010

HI U GOOD PEOPLE DOIN, , , , , , ,

This may not come out too good, but think through it before you hit on me. On Oct 1 , we stop shaking hands at our little country church in Ten Mile. At first , the congregation was slightly irritated but some are now telling me that I'm smart.

We don't get much sun so we up our Vitamin D 3 to 5000 I u's /day. We stopped the flu vaccine years ago. Had you rather have the flu or mercury poisoning? Also , we shop stores before the crowds and know that there are a jullion germs on each buggy handle, door knobs, etc. So we carry anti-bacteria jels with us and wash our hands often.

Come April 1, we start shaking hands again, and cut back on our Vitamin D3. The Intelligent One created the sun which lets you make you own Vitamin D. Ain't that wonderful. Since I's not PC, I wish you all a Merry CHRISTmas. =========ROBERT HENRY=============

Cod Liver Oil
Posted by Valerie (New Zealand ) on 10/28/2017

I think Less vitamin A is required than vitamin D actually and it's easier to reach vitamin A toxicity with Cod LIver Oil, but that the amount of d in the Oil is quite low, and not enough to address Vitamin D deficiency so often has little effect for people suffering symptoms of D deficiency. You are far better off taking higher doses of D and a fish oil capsule. I noticed some D is placed into Safflower Oil Capsules. The fish Oil (Omega 3s) would balance out any daily omega 6's. I think vitamin A is at lower doses in some Fish Oils making it less toxic.

D3 and Cod Liver Oil
Posted by Deirdre (Earth Clinic) on 02/28/2010
1 out of 5 stars


This is a reminder for everyone taking D3 to please check the list of ingredients on their bottles of vitamin D3 to see they contain Cod Liver Oil (and therefore vitamin A). I just checked the list of ingredients on my huge bottle of D3 softgels that I got at Costco (Kirkland brand) a couple of weeks ago and saw that they contain Cod Liver Oil. What a bust! The bottle does not list vitamin A in the Supplement Facts section, only vitamin D3.

"Cod liver oil contains more vitamin A and more vitamin D per unit weight than any other common food. One hundred grams of regular cod liver oil provides 100,000 IU of vitamin A, almost three times more than beef liver, the next richest source; and 10,000 IU vitamin D, almost four times more than lard, the next richest source. Of course, cod liver oil is only consumed in small amounts, but even a tablespoon (about 15 grams) provides well over the recommended daily allowance for both nutrients."


The problem is that even small amounts of vitamin A negate the benefits of vitamin D. From the Dr. Cannell's latest newsletter:

"... the benefits of vitamin D are almost entirely negated in those with the highest vitamin A intake. And the retinol intake did not have to be that high in these older adults to begin to negate vitamin D's effects, about 3,000 IU/day."


Posted by Selena (Chula, Ga, Usa) on 02/16/2010

I read the information on your site about fibromyalgia and flouride poisoning but I didn't find any on the link between Vit. D deficiency and fibro. I just want to be sure that those suffering from this illness are aware of the belief that fibro. is considered by some to be an adult form of rickets. It manifests itself with signs of so many symptoms because if the body is deficient in Vit. D then it will become deficient in all of the minerals the body needs because without the vit. D in the colon minerals cannot be utilized and absorbed by the body. There is no substitute for the natural vit. D produced by the body by being exposed to natural sunlight....especially women are deficient because all of their makeup and body lotions block the UV rays of the sun. If you are suffering from fibromyalgia, please research the link between fibro. and vit. D deficiency.