We’ve heard a lot about Vitamin D in the past few years. There have been studies linking low Vitamin D levels to a host of health issues, from heightened risk of cardiovascular disease, to higher probability of developing the flu, especially during the winter season, when you get less exposure to the sunshine that allows the body to produce its own supply of the vitamin.
Now here’s an interesting meta-analysis (=review of previously published research) that looks at the connection between long-term use of Vitamin D3 supplements (“long-term” defined, in this case, as more than three years). Reviewing data from 42 earlier trials, this investigation found that those who supplemented with Vitamin D for longer than three years had a significant reduction in mortality. Specifically, this research found that the following groups showed a lower risk of death when supplementing with Vitamin D over a period longer than three years: women, people under the age of 80, those taking a daily dose of 800IU or less of Vitamin D, and those participants with vitamin D insufficiency (defined as a baseline 25-hydroxyvitamin D level less than 50 nmol/L).
Here’s the conclusion reached by the researchers:
The data suggest that supplementation of vitamin D is effective in preventing overall mortality in a long-term treatment, whereas it is not significantly effective in a treatment duration shorter than 3 years. Future studies are needed to identify the efficacy of vitamin D on specific mortality, such as cancer and cardiovascular disease mortality in a long-term treatment duration.
Our comment: We’re not surprised that supplementing over a period of years proves, in this review, to be more beneficial than briefer periods of supplementing. Vitamin D, like many supplements, shouldn’t be seen as treatment for an acute condition. It doesn’t act like an antibiotic, which may clear up an infection with a couple weeks of treatment. Instead, think of the body as having a long-term, continual need for Vitamin D; and note as well that seasonal change, or a particular health status (for example, being HIV+), may lead to deficiency and thus increase your need for supplementing. We were somewhat surprised to see that a significantly lowered risk of mortality was found even with a moderate rate of supplementation (800 IU daily dose). On this Blog you can read about other research that links decreased risk of flu, for example, with a daily Vitamin D dose of 2000IU. At any rate, there are no known “adverse events” at either of these doses of the vitamin, so not to worry, whether you’re following the lower or a higher recommendation.
See the NYBC catalog for Vitamin D3 offerings:
Zheng Y, et al. Meta-analysis of long-term vitamin D supplementation on overall mortality. PLoS One. 2013 Dec 3;8(12):e82109. doi: 10.1371/journal.pone.0082109.