Taking a high dose of vitamin D makes older people more likely to fall, says a study published today by the American Medical Association. As I wrote here three months ago, taking vitamin D can do amazing things for people who need it, while it's a growing problem for those who overuse it.
This latest study was conducted in Switzerland, among men and women mostly in their 70s who had fallen in the past. It compared the effects of a monthly dose of 24,000 IU of vitamin D (equivalent to 800 IU per day) to two higher doses of vitamin D: 60,000 IU or 24,000 IU with 300 micrograms of calcifediol -- a super-potent form of vitamin D. Although the higher-doses raised vitamin D levels more than the lower dose, they were each associated with an increased risk of falls over the course of a year (about 66 percent fell) compared with the lower dose (47.9 percent fell). Seniors who were not deficient in vitamin D (that is, their blood levels were already at or above 20 ng/mL) but were still given 60,000 IU of vitamin D per month experienced the most falls. Similarly, people whose levels reached 45 to 99 ng/mL (abnormally high levels!) had nearly twice as many falls as those whose levels reached 21 to 30 ng/mL.
What's the bottom line from this and other recent studies of vitamin D? Only take what you need -- a good lesson any time. More specifically, if your vitamin D blood level is below 20 ng/mL, you may benefit from supplementing with vitamin D. If it's already in the 20 to 30 ng/mL range, just get the recommended daily intake of vitamin D (800 IU for those over 70 and 600 IU for everyone else, according to the Institute of Medicine of the National Academies), which you may already get from sun exposure, vitamin D-fortified dairy products, and other foods.
If you need a supplement, you may want to check product reviews by my company, ConsumerLab.com, to find out which supplements do, or don't, contain what they claim and how to best use them.