Vitamin D can be produced by exposure of the skin to sunlight and helps maintain the body’s calcium levels, which in turn keeps bones, teeth and muscles healthy. In the spring and summer, most people are able to get enough vitamin D through sunlight and diet, but in the fall and winter, due to insufficient exposure to sunlight, the main sources of vitamin D are specific foods such as oily fish, egg yolks, and red meat. There seems to be a recent controversy regarding vitamin D supplementation. Some research results have come to opposite conclusions. First, I would like to share with you one of the results just published this week. 1, BMJ amazing discovery: vitamin D supplementation to prevent colds or flu February 15, published in the British Medical Journal, entitled “Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis. infections: systematic review and meta-analysis of individual participant data,” claims that vitamin D supplementation can save more than 3 million people in the United Kingdom from catching a cold or the flu each year. Previous trials using vitamin D supplements to prevent infections have yielded mixed results. In this study, scientists pooled data from 25 independent trials (involving 11,321 people) in hopes of finding a definitive answer. Overall, the study said that one in 33 people who took vitamin D supplements would be protected from infection. Public HealthEngland (PHE) has recommended that everyone take vitamin D supplements in the fall and winter. At the same time, PHE also recommends that those who rarely get sun exposure take vitamin D supplements throughout the year. 2, the controversy continues According to the BBC, the new research has also caused controversy. louis Levy, head of nutrition science at PHE, believes that the study fails to provide enough evidence to support the recommendation of vitamin D supplementation to reduce the risk of respiratory infections. But Professor Martin Hewison of the University of Birmingham said: “Although this finding is striking, I agree with the authors. This study supports the idea that vitamin D has new indications in addition to its benefits for bone health. 3, vitamin D deficiency, may be overstated In fact, the controversy over vitamin D supplementation goes far beyond that. Last November, a review published in NEJM titled “Vitamin D Deficiency – Is There Really a Pandemic?” said that vitamin D deficiency may be overstated. Many people think they need more vitamin D, but they don’t actually need that much. In fact, less than 6 percent of Americans (ages 1-70) are vitamin D deficient, and only 13 percent of Americans are at risk for vitamin D deficiency. The authors of the article concluded that these deficiency levels do not constitute a disease. 4, not enough to prevent disease A study published in the BMJ the same month said the current evidence is not enough to support the use of vitamin D supplements to prevent disease. Researchers said that for those with vitamin D deficiency, they should be advised to get more sunlight and eat a sensible diet and use low-dose supplements, but for most people, maintaining a healthy, balanced diet and regular short periods of sun exposure is all that is needed. In addition, studies say that vitamin D supplementation does not improve musculoskeletal conditions in cases such as falls or fractures. There is also no high-quality evidence that vitamin D supplementation is beneficial for other conditions, such as heart disease, stroke and certain cancers. The authors concluded that if vitamin D supplementation does have a benefit, it is most likely to be observed in groups with severe vitamin D deficiency.