2400 Units of Vitamin D a Day for Fibromyalgia

Fibromyalgia, one of the most common joint and muscle diseases, afflicting millions of Americans, is characterized by widespread musculoskeletal pain, often accompanied by other symptoms, such as fatigue. The medical profession used to think it was all in people’s heads, “but today there is irrefutable evidence” that it is indeed a disorder of the body and not just the mind.

Back in 2003, an influential paper was published out of the Mayo Clinic in which a shocking 93 percent of fibromyalgia-type patients were found to be vitamin D deficient, so the researchers concluded that all such patients are at high risk of severe vitamin D deficiency. Wait a second, said the skeptics. There was no control group, and where’s the Mayo Clinic located? Minnesota. Maybe 90 percent of everyone in Minnesota is deficient in vitamin D.

When controlled studies were done, some did indeed find that those suffering from these kinds of pain syndromes were significantly more likely to be D deficient, but other studies did not find this. Even if all the studies did have the same findings, though, that doesn’t mean that low vitamin D levels cause fibromyalgia. Maybe chronic, widespread pain disorders like fibromyalgia cause low vitamin D. After all, it’s the sunshine vitamin, and perhaps fibromyalgia patients aren’t running around outside as much as healthy controls. To know if vitamin D is contributing to the disease, you have to put it to the test. 

Various studies found that the majority of those with pain syndromes and low D levels appeared to benefit from vitamin D supplementation, and clinical improvement was evident in up to 90 percent of patients. But these studies weren’t controlled either. Maybe the subjects would have gotten better on their own without the supplements, or maybe it was the placebo effect. There are many examples in the medical literature of treatments that looked great in uncontrolled trials, like hyperbaric oxygen therapy for multiple sclerosis, but when put to the test in randomized controlled trials, they failed miserably.

And, that’s what seemed to happen in the first randomized controlled trial of vitamin D for a fibromyalgia-type syndrome in 2008. As you can see at 2:55 in my video The Best Supplement for Fibromyalgia, researchers saw no significant difference in pain scores, though the study only lasted three months, and, in that time, the treatment was only able to get the vitamin D blood levels up to about 30. Unfortunately, no controlled study had ever been done pushing levels any higher, until 2014. As you can see at 3:23 in my video, fibromyalgia patients were given up to 2400 units of vitamin D a day for 20 weeks and their D levels rose up to about 50. Then, once they stopped the vitamin D, their levels came back down to match the placebo. That was reflected in their pain scores: a significant drop in pain severity while they were on the D and then back to baseline when they came off of it. The researchers concluded “that this economical [in fact, over-the-counter] therapy with a low side effect profile may well be considered in patients with FMS [fibromyalgia syndrome].”


What changes in our diet may help combat fibromyalgia? See my videos Fibromyalgia vs. Vegetarian and Raw Vegan Diets and Fibromyalgia vs. Mostly Raw & Mostly Vegetarian Diets.

What else can vitamin D supplements do? Check out:

What’s the best way to get vitamin D? See:

In health,

Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:

Vitamin D Supplements for Increasing Aging Muscle Strength

We have known for more than 400 years that muscle weakness is a common presenting symptom of vitamin D deficiency. Bones aren’t the only organs that respond to vitamin D—muscles do, too. However, as we age, our muscles lose vitamin D receptors, perhaps helping to explain the loss in muscle strength as we age. Indeed, vitamin D status does appear to predict the decline in physical performance as we get older, with lower vitamin D levels linked to poorer performance. As I discuss in my video in my video Should Vitamin D Supplements Be Taken to Prevent Falls in the Elderly?, maybe the low vitamin D doesn’t lead to weakness. Rather, maybe the weakness leads to low vitamin D. Vitamin D is the sunshine vitamin, so being too weak to run around outside could explain the correlation with lower levels. To see if it’s cause and effect, you have to put it to the test.

As you can see at 1:01 in my video, about a dozen randomized controlled trials have tested vitamin D supplements versus sugar pills. After putting them all together, we can see that older men and women taking vitamin D get significant protection from falls, especially among those who had started out with relatively low levels. This has led the conservative U.S. Preventive Services Task Force, the official prevention guideline setting body, and the American Geriatric Society to “recommend vitamin D supplementation for persons who are at high risk of falls.”

We’re not quite sure of the mechanism, though. Randomized controlled trials have found that vitamin D boosts global muscle strength, particularly in the quads, which are important for fall prevention, though vitamin D supplements have also been shown to improve balance. So, it may also be a neurological effect or even a cognitive effect. We’ve known for about 20 years that older men and women who stop walking when a conversation starts are at particularly high risk of falling. Over a six-month timeframe, few who could walk and talk at the same time would go on to fall, but 80 percent of those who stopped walking when a conversation was initiated ended up falling, as you can see at 2:14 in my video.

Other high-risk groups who should supplement with vitamin D include those who have already fallen once, are unsteady, or are on a variety of heart, brain, and blood pressure drugs that can increase fall risk. There’s also a test called “Get-Up-and-Go,” which anyone can do at home. Time how long it takes you “to get up from an armchair, walk 10 feet, turn around, walk back, and sit down.” If it takes you longer than ten seconds, you may be at high risk.

So, how much vitamin D should you take? As you can see at 3:00 in my video, it seems we should take at least 700 to 1,000 units a day. The American Geriatric Society (AGS) recommends a total of 4,000 IU a day, though, based on the rationale that this should get about 90 percent of people up to the target vitamin D blood level of 75 nanomoles per liter. Although 1,000 IU should be enough for the majority of people, 51 percent, the AGS recommends 4,000 IU to capture 92 percent of the population. That way, you don’t have to routinely test levels, since 4,000 IU will get most people up to the target level and “is considerably below the proposed upper tolerable intake of 10,000 IU/d.” The AGS does not recommend periodic mega-doses.

Despite the AGS’s recommendation, because it’s hard to get patients to comply with pills, why not just give people one megadose, like 500,000 units, once a year, perhaps when they come in for their flu shot? That way, every year, you can at least guarantee an annual spike in vitamin D levels that lasts a few months, as you can see at 4:00 in my video. It’s unnatural but certainly convenient, for the doctor at least. The problem is that it actually increases fall risk, a 30 percent increase in falls in those first three months of the spike. Similar results were found in other mega-dose trials. It may be a matter of too much of a good thing. See, “vitamin D may improve physical performance, reduce chronic pain, and improve mood” so much that people start moving around more and, thereby, increase fall risk. When you give people a whopping dose of vitamin D, they get a burst in physical, mental, and social functioning, and it may take time for their motor control to catch up to their improved muscle function. It would be like giving someone a sports car when they’ve been used to driving a beater. You’ve got to take it slow.

It’s possible, too, that such unnaturally high doses may actually damage the muscles. The evidence the researchers cite in support is a meat industry study showing you can improve the tenderness of steaks by feeding cattle a few million units of vitamin D. The concern is that such high doses may be over-tenderizing our own muscles, as well. Higher vitamin D levels are associated with a progressive drop in fracture risk, but too much vitamin D may be harmful, as you can see at 5:29 in my video.

The bottom line is that vitamin D supplementation appears to help, but the strongest and most consistent evidence for prevention of serious falls is exercise. If you compare the two, taking vitamin D may lower your fall risk compared to placebo, but strength and balance training with or without vitamin D may be even more powerful, as you can see at 5:41 in my video.


Other studies in which vitamin D supplements have been put to the test in randomized placebo-controlled studies, effectively proving—or disproving—their efficacy, are featured in videos such as:

That brings up a number of important questions, which I answer in these videos:

Unfortunately, most supplements are useless—or worse. Here are some additional videos on supplements I’ve produced that may be of interest to you:

For more on the benefits of exercise, see Longer Life Within Walking Distance and How Much Should You Exercise?

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:

What to Take for Menstrual Cramps

In my video Ginger for Migraines, I described how ginger works as well as the leading “drug” in the treatment of migraines, “one of the most common causes of pain syndromes,” affecting as much as 12 percent of the population. Twelve percent is “common”?

How about menstrual cramps, which plague up to 90 percent of younger women? You can tell this study was written by a guy because he emphasizes the absenteeism and all the “lost productivity” for our nation. Menstrual cramps also just really hurt.

Can ginger help? As I discuss in my video Benefits of Ginger for Menstrual Cramps, women took a quarter teaspoon of ground ginger powder three times a day during the first three days of menstruation, and pain dropped from seven on a scale of one to ten down to a five, whereas there was no significant change in the placebo group, as you can see at 0:56 in my video. Most women in the placebo group said their symptoms stayed the same, whereas those unknowingly in the ginger group said they felt much better.

A subsequent study found that even just an eighth of a teaspoon three times a day appeared to work just as well, dropping pain from an eight to a six and, in the second month, down to a three. The “alleviation of menstrual pain was more remarkable during the second month of the intervention,” and study participants had only been taking the ginger for four days, not the whole month, suggesting it might work even better if women use ginger every period. 

What about the duration of pain? As you can see at 1:52 in my video, a quarter teaspoon of ground ginger powder three times a day not only dropped the severity of pain from about a seven down to a five but also decreased the duration of total hours in pain from 19 hours down to about 15 hours, indicating that three quarters of a teaspoon of ginger powder a day for three days is a safe and effective way to produce pain relief in college students with painful menstrual cramps, compared to placebo, capsules filled instead with powdered toast. But women don’t take breadcrumbs for their cramps. How does ginger compare with ibuprofen? An eighth of a teaspoon of ginger powder four times a day for three days versus 400 milligrams of Motrin were put to the test, and the ginger worked just as well as the drug of choice, as you can see at 2:40 in my video.

If you do take the drug, though, I was surprised to learn that it may be better to take drugs like ibuprofen and naproxen on an empty stomach because that may speed up the pain relief and help keep people from taking higher doses.


I’ve touched on this effect before in Ginger for Nausea, Menstrual Cramps, and Irritable Bowel Syndrome. What else can this amazing plant do? See, for example:

What else can really help with cramps, PMS, and cyclical breast pain? Check out:

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations: