Many studies have now found high association between vitamin D levels and COVID-19 severity and mortality. Such studies showed that patients with COVID-19 had significantly lower vitamin D levels. In addition, fewer was significantly higher in patients who had deficient vitamin D levels compared with patients who had sufficient levels. Additionally, it has been found that older adults with vitamin D deficiency and COVID-19 had worse morbidity outcomes compared with those who were not vitamin D deficient.

Vitamin D is a fat-soluble vitamin that plays a number of critical roles in body. This nutrient is especially important for immune system health. Since, it is a group of fat-soluble compounds responsible for intestinal absorption of calcium, magnesium, and phosphate, and for a variety of additional biological effects; low levels of vitamin D can increase the likelihood of developing multiple acute and chronic ailments. A weaker immune system means week body’s defence against infection and disease.

Highlighting the importance of Vitamin D3 in fighting COVID 19, Dr. Ashu Rastogi Asso Professor, Dept of Endocrinology, PGI Chandigarh said, recently, vitamin D deficiency has been linked with susceptibility to COVID-19 and severity of outcomes for patients with COVID-19. A prospective, interventional study found that a high dose of calcifediol reduced the need for intensive care stays in patients infected with COVID-19. Because vitamin D deficiency has been shown to potentially increase the risk of severe respiratory infections, vitamin D supplements are suggested for prevention and treatment of COVID-19 complications, especially acute respiratory disease. Nowadays many brands of Vitamin D supplementation are available in market like D3 Must, Caldikind, Calshine, etc.

It is noticed that those receiving vitamin D supplementation have fewer respiratory tract infections, says Dr Ashu Rastogi, Associate Professor, Department of Endocrinology, PGI Chandigarh.

According to the SHADE study published by BMJ and led by Dr Rastogi and his team, greater proportion of vitamin D-deficient individuals with SARS-CoV-2 infection turned SARS-CoV-2 RNA negative with a significant decrease in fibrinogen on high-dose cholecalciferol supplementation.

Dr Ashu Rastogi said: “We have seen that seven days high dose of Vitamin D3 (60000 IU) supplementation helps in coronavirus clearance.

Given the evidence supporting the role of vitamin D in modulating immune function, and the impact of vitamin D supplementation on vitamin D-deficient patients with COVID-19, practical recommendations should be synthesised as follows:

► Current public health guidelines for optimising vitamin D status should be followed always

► Patients hospitalised with COVID-19 should have baseline serum 25(OH)D concentrations measured and should be supplemented to a level >30ng/mL (optimal 40–60ng/mL), especially when the baseline level is <10ng/mL

► In COVID-19 patients with 25(OH)D serum concentrations under 20ng/mL the recommended dose for correction of deficiency is 6000–7000 oral IU/ day for 6–8 weeks. For maintenance, the dose varies from 2000 to 3000 oral IU/day depending on the age and clinical condition of the individual up to reach optimal concentrations.

► When it is not possible to measure baseline 25(OH)D concentrations in COVID-19 patients, it seems essential supplementing with 2000–3000 oral IU per day up to the suggested optimal serum concentrations (40–60ng/mL).

Though India is a subtropical country with adequate sunlight, vitamin D deficiency is prevalent. Sunlight rapidly inactivate SARS-CoV-2 on surfaces, suggesting that there may be an environmental benefit associated with vitamin D as a result of sun exposure. It is highly important for people to understand the importance of Vitamin D so that they can take relevant medications as against the disease.