Benefits of Taking Vitamin D Supplements
Background: It is well known that Vitamin D helps to protect bones from fractures. However, whether taking Vitamin D pills helps the immune system is controversial.
Study: Researchers at the Queen Mary University of London pooled results from 25 different studies to find out if Vitamin D supplements reduce the number of respiratory infections.
The study results were published on-line in the February 15, 2017, issue of the British Medical Journal (doi: 10.1136?bmj.i6583).
Results: A total of 11,321 subjects were studied in the 25 different research trials. Taking Vitamin D supplements reduced the risk of a sudden (acute) respiratory tract infection among all subjects by 12%. This change was statistically significant compared with those subjects taking a placebo (sham or pretend) treatment. The effect was stronger in those who had a low blood level of 25-hydroxyvitamin D (less than 25 nmol/liter).
Conclusions: Vitamin D supplementation was safe and protected against acute respiratory tract infections. Those who were deficient in Vitamin D experienced the most benefit.
My Comments: The body produces it own Vitamin D when exposed to sunlight. Some foods in the US are fortified with Vitamin D, such as milk, orange juice, and cereals. Sardines and salmon naturally contain high levels of Vitamin D.
How much Vitamin D should I take if I decide to supplement? First, you may wish to ask your health care provider to measure your level of 25-hydroxyvitamin D in the blood to find out if you are low. People at risk of Vitamin D deficiency are those with celiac disease (a digestive disorder) and people who cover up most their skin or get very little exposure to the sun.
Dr. Steven Abrams of the Dell Medical School at the University of Texas at Austin commented on the study findings: “If you’re deficient, getting an adequate amount will make a difference.”
The Institute of Medicine recommends that most adults need about 600 international units (IU) of Vitamin D per day. Adults over 70 years of age are advised to increase their intake to 800 IUs. The Institute warns against taking more than 4,000 IUs a day.