Vitamin C or Vitamin D: Which Is Better for Supporting Immunity According to Recent Studies?

SadaNews - Both Vitamin C and Vitamin D support the immune system, but they do so in different ways. As the cold and flu season approaches, these two vitamins come back into focus as popular options for enhancing immunity. However, the effect of each largely depends on your current levels in the body, as one may be more important than the other in protecting you from infections.

Vitamin C and Its Role in Supporting White Blood Cells

Vitamin C is one of the most well-known supplements supporting immunity, and its benefits start at the cellular level. It is a powerful antioxidant, helping to protect cells from damage and may contribute to the prevention of certain diseases, according to "verywellhealth".

Inside the body, Vitamin C enhances the response of white blood cells when exposed to viruses, protects tissues from oxidative stress resulting from immune system reactions, and supports skin health and collagen production, strengthening the body's first line of defense against germs.

Despite these roles, Vitamin C does not serve as a magic shield that prevents illness. Research indicates that it does not prevent colds in most people, but it may reduce symptom severity and shorten the duration of illness when taken regularly, not just after symptoms appear.

Most adults need about 75–90 milligrams of Vitamin C daily from food, while immune support studies use doses ranging from 200 to 500 milligrams daily. Since Vitamin C deficiency is relatively rare, high doses may not provide additional benefits and could cause stomach upset.

Vitamin D and Its Role in the Body's Response to Viruses

Vitamin D plays a different role; it acts more like a "messenger" that directs the immune system on how to perform its tasks. Adequate levels help immune cells recognize and deal with viruses, reduce inflammation, and support respiratory health.

Research shows that people with low Vitamin D levels are more susceptible to respiratory infections. For these individuals, taking supplements regularly may help reduce this risk, especially during winter or for those not getting enough sunlight.

Daily requirements for most adults range between 600 and 800 international units, yet many do not achieve this level, which leads some doctors to recommend higher doses based on blood tests. Unlike Vitamin C, it is difficult to obtain sufficient amounts of Vitamin D from food alone, making sun exposure or supplements essential.

Which is Better for Immunity: Vitamin C or Vitamin D?

Studies suggest that both contribute to supporting immunity, but through different mechanisms, and it cannot be said that one is absolutely better than the other.

Vitamin D supports overall immune system efficiency and may reduce the risk of certain infections, especially in those who are deficient in it.

Vitamin C supports the activity of immune cells and may help reduce the severity and duration of cold symptoms.

Getting adequate amounts of both vitamins together is essential for maintaining an efficiently functioning immune system.

How and When Is It Recommended to Take Vitamin C or Vitamin D?

The effect of both vitamins is best when taken regularly, not just after symptoms appear.

Vitamin D works gradually in the long term and is not a treatment after infection, so it is advised to maintain its levels year-round. In contrast, Vitamin C may provide limited support during colds but is more effective when taken regularly.

Many people turn to Vitamin D during fall and winter when sunlight exposure decreases and respiratory diseases increase. Vitamin C, on the other hand, is often not necessary as a supplement since most people get enough from their diet. The two vitamins can be taken together safely, as they do not interfere with each other.