12 Surprising Pros and Cons of Vitamin D Supplements

2. Immune System Modulation: A Double-Edged Sword

Vitamin D is pivotal in modulating the immune system, enhancing the pathogen-fighting effects of monocytes and macrophages—white blood cells that are important parts of your defense system—and decreasing inflammation. This has led to suggestions that vitamin D supplements could help in reducing the risk of infections, including respiratory tract infections. However, the immune system is a complex network, and excessive vitamin D can potentially overstimulate immune responses, leading to autoimmune issues. Therefore, while vitamin D can be a valuable ally in maintaining immune health, it should be approached with caution and personalized medical advice.