Annual mega-dose of vitamin D doesn't reduce fractures, study finds

Sufficient vitamin D is vital to bone health and preventing the bone-thinning disease osteoporosis. But a new study shows an experimental therapy involving a once-a-year mega-dose of vitamin D did not prevent bone fractures and actually increased the risk of falls and fractures.

Researchers in Australia gave a single, annual dose of 500,000 international units of vitamin D or a placebo to 2,256 women, ages 70 and older, at high risk for fracture. But after three to five years, the study showed that 74% of the women in the vitamin D group had at least one fall compared with 68% of the women in the placebo group. Women in the vitamin D group had 171 fractures compared with 135 in the placebo group.

Vitamin D supplementation of 800 IU a day is known to be important for good bone health. It's not clear why an annual mega-dose may backfire. It's possible that vitamin D improved the women's overall health and well-being to the extent that they were more active and mobile and had more opportunities to fall. But no matter, said the authors of a commentary accompanying the study, it's safe and effective to take the vitamin at lower doses daily, weekly or monthly.

The study was published Tuesday in the Journal of the American Medical Assn.

— Shari Roan

Comments

[Andrew]

The study design is without physiologic basis and doomed to fail. This is not how vitamins or hormones (which is what Vitamin D really is) work in the body. This is as logical as eating a very LARGE meal and calling it a failure if you become hungry 2 days later ... OR ... it is like taking a MEGA dose of insulin or thyroid hormone and considering it a failure if a week later you are found to be hyperglycemic or hypothyroid again. Illogical. Shame on the researchers for wasting funds on the research. Shame on JAMA for publishing this nonsense. Shame on LA Times for reporting it. It is drivel.

[Jane]

Maybe the people that were taking the vitamin were just more clumsy.