Vitamin D, also called the sunshine vitamin, is an important micro-nutrient, a fat-soluble steroid hormone that exists in different forms. 25-hydroxyvitamin D is the primary circulating form, the biologically active form is 1,25-dihydroxyvitamin D.

The Classical Functions of Vitamin D is to mediate several physiological processes, including bone and extra-skeletal metabolism, cardiovascular and calcium homeostasis, and, most importantly, immune functions. It has both anti-inflammatory and immune-regulatory properties,? and is vital for the activation of immune system defense mechanism.??

Our body’s innate and adaptive immune system provides protection against viral infections and aids in regulating cytokine levels. Vitamin D has been widely implicated in enhancing the immune response and suppressing the cytokine storm.

Vitamin D induces antiviral effects by both direct and indirect mechanisms, immunomodulation, the interplay between major cellular and viral elements, induction of autophagy and apoptosis, variation of genetic and epigenetic factors.??

There are plausible pathways whereby vitamin D deficiency can impair immune function, resulting in both over activity, increased risk of autoimmune disease as well as immune suppression with poorer resistance to infection. Vitamin D status may influence the bacterial flora that constitute the microbiome and affect immune function through this route.?

Vitamin D supplementation could reduce severe COVID-19 complications and mortality.?

Major Source of production of Vitamin D is sunlight. Exposure of the skin to ultraviolet radiation causes the production of a range of chemicals. It activates 7 Dehydrocholestrol in skin into its active form - Cholecalciferol. The best time to soak yourself in the sun to get the maximum vitamin D is between 10 am to 3 pm.

At this time, the UVB rays are intense and it is also said that the body is more efficient in making Sunshine vitamin at this time. Expose your arms, legs, back and abdomen to get more vitamin D. Do not forget to expose your back as it allows your body to produce the maximum vitamin D. You can choose to wear a tank top and shorts, protect your face and eyes.?

Food Sources include egg yolk, Chicken breast , oily fish – such as salmon, sardines, herring and mackerel, mushrooms, red meat, liver and fortified foods.?

Regular inclusion of egg omelette, boiled eggs, grilled fishes, fish gravy, chicken sandwich, chicken salad, chicken rolls, shrimp and noodles and creamy mushrooms will improve the vitamin D status in the body. Chicken, an excellent red meat alternative, is high in protein, which is essential for growth and development, as well as other nutrients including iodine, iron, zinc, and vitamin B12.?

• Factors affecting absorption:??

Age: Vitamin D is a fat soluble vitamin but as the body ages its stores are depleted which makes the body more susceptible to be easily attacked by the virus. The deficiency predisposes sensitive population (elderly and individuals with underlying health conditions) to the full effects of the virus.?

Exposure to ultraviolet radiation?

Any process that alters the amount of UVB (Ultra Violet B rays) radiation entering the skin may significantly affect vitamin D3?

Melanin efficiently absorbs electromagnetic radiation across the entire UV and visible light range and thus competes with 7-dehydrocholesterol for UVB photons. Compared to individuals with lightly-pigmented skin, those with high concentrations of melanin (darkly-pigmented) require longer UV exposure times to generate an equivalent amount of vitamin D3. UVB rays are important for making vitamin D and sunscreen can stop the skin from absorbing sunlight.?

Skin temperature plays an important role in cutaneous vitamin D3 synthesis.?

Conditions such as celiac disease, chronic pancreatitis, Crohn's disease, and cystic fibrosis can all affect the intestines, preventing them from absorbing vitamin D found in food. BMI (body mass index) higher than 30 reduces the absorption rate.??

Supplementation: If you choose to take vitamin D supplements, 10 micrograms a day will be enough for most people. Taking too many vitamin D supplements over a long period of time can cause too much calcium to build up in the body (hypercalcaemia). This can weaken the bones and damage the kidneys and the heart. Do not take more than 100 micrograms (4,000 IU) of vitamin D a day as it could be harmful?

Dearth of treatment for COVID-19 leaves us with no choice but to take precautionary and prophylactic measures to stand a better chance to fight this pandemic. Hence, maintaining adequate Vitamin D levels is vital to prevent getting infected or to ward off the infection.??

(The author is a Dietician, Yoga Therapist & Naturotherapist. Views expressed are personal, and do not necessarily reflect those of Outlook Magazine.)?