Vitamin D is a fat-soluble vitamin that is essentially required to play a variety of roles in the body. It is well-established that we need vitamin D for the absorption of calcium and phosphorus, for strong bones and bone density. But it is also needed for the smooth functioning of our immune cells.
Our immune system has T-cells which are called killer cells. These cells protect us from foreign bodies as they are perfect in differentiating between outside invaders and “self cells.” Vitamin D strengthens our immune system by regulating these T-cells. On detecting the presence of any foreign pathogen in the presence of vitamin D3, “naive” T-cells gets activated into active killer T-cells. Hence, it plays a critical role in protecting us and promoting immune response.
Adequate levels of vitamin D in the body prevents inflammation and decreases our susceptibility to diseases and infections. To protect against this deadly coronavirus, social distancing and maintaining personal hygiene is the key. Coronavirus attack our lungs and respiratory system. Treatment response and rate of recovery depend on how strong is our immune health. Vitamin D is one such essential vitamin that is required by our immune system to function substantially.
So now the question arises that can vitamin D protect against COVID 19.
COVID 19 affects our respiratory system and several studies have shown that deficiency of vitamin D is associated with an increased likelihood of lung infections.
Under a study published in the British Medical Journal in 2017, analysis of vitamin D supplementation was done to check the efficacy in preventing acute respiratory tract infections. There was a total of 10933 participants and supplementation with vitamin D3 demonstrated a better immune response with a reduced risk of respiratory tract infections.
In another study of 2009 published in Clinical and Experimental Immunology, supplementation of vitamin D was observed among people having tuberculosis, asthma, COPD, flu and the common cold. Researchers believed that maintaining vitamin D serum levels above 30 ng/L is essential to defend against any lung-related disease.
As per WHO, it is imperative to maintain adequate vitamin D levels among children and adults to enhance innate immunity, for the secretion of antimicrobial peptides which boosts mucosal defences. It prevents rickets and pneumonia, especially among children.
In addition, dietary guidelines for hospitalised patients due to COVID 19 as given by India Association for Parenteral and Enteral Nutrition, 2020 also recommended to focus on vitamin D levels and provide supplementation, if required to restock the balance.
For all these reasons, it is evident that vitamin D significantly contributes to boosting our immunity and may protect us from diseases like COVID 19.
Our daily need for vitamin D is 600-800 IU as per ICMR, under minimum sunlight exposure. However, in case of deficiency supplementing with higher doses of vitamin D3 might prove favourable.
It is important to note that vitamin D alone is not a resolution to treat or prevent coronavirus. It is important to consume a well-balanced diet rich in all other essential nutrients as well, along with an active lifestyle, in order to stay healthy and foster immunity.
Martineau A R, Jolliffe D A, Hooper R L, GreenbergL, Aloia J F, Bergman P et al. Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data BMJ 2017; 356:i6583 doi:10.1136/bmj.i6583
Hughes, D. A., & Norton, R. (2009). Vitamin D and respiratory health. Clinical and experimental immunology, 158(1), 20–25. https://doi.org/10.1111/j.1365-2249.2009.04001.x
Martineau, A. R., Jolliffe, D. A., Greenberg, L., Aloia, J. F., Bergman, P., Dubnov-Raz, G., Esposito, S., Ganmaa, D., Ginde, A. A., Goodall, E. C., Grant, C. C., Janssens, W., Jensen, M. E., Kerley, C. P., Laaksi, I., Manaseki-Holland, S., Mauger, D., Murdoch, D. R., Neale, R., Rees, J. R., … Hooper, R. L. (2019). Vitamin D supplementation to prevent acute respiratory infections: individual participant data meta-analysis. Health technology assessment (Winchester, England), 23(2), 1–44. https://doi.org/10.3310/hta23020