Is there a connection between Vitamin D and immunity against COVID-19?

As some cities in India open back up and people are getting back to work, many are searching for ways to ramp up their immunity in an effort to protect themselves from COVID-19. Vitamin supplementation is one of the key suggestions you will hear made for this, especially Vitamin D, which many Indians are found to be deficit of. Not sure whether or not you should add it to your routine ASAP? We asked doctors for their take.

How does Vitamin D boost overall health?

Fat-soluble Vitamin D acts as a hormone and is essential for several functions in our body. One of its primary functions is to affect and increase calcium absorption from your gut. It also prevents the removal of phosphorous and calcium through the urine and increases the blood level of calcium, all of which makes it essential for your bones. “Vitamin D is important as it helps increase bone mineral density and prevents bone fractures, enhances your mood, lung function, and even protects against heart disease,” says Dr Shreedhar Archik, consultant orthopaedic, Global Hospital Mumbai. We need calcium for all muscle contraction, so balanced Vitamin D levels are associated with better heart health too.

Vitamin D is important for proper immune function. As an immunomodulator, it regulates the body's response to germs by communicating with immune cells that produce enzymes. Some preliminary research has shown that Vitamin D deficiencies may play a role in COVID-19 infection rates, as a lower immunity is more at risk for respiratory illnesses. While supplementation can't protect you from contracting the disease, doctors suggest that maintaining balanced levels can certainly help your ability to fight it.

Food has calcium in variable amounts, but Vitamin D helps to increase the absorption. “It exists in food in two forms—Vitamin D3 is of animal origin and Vitamin D2 is of plant origin. It is involved in the regulation of specific genes, improving or activating the immune system, says Amreen Shaikh, head nutritionist, Wockhardt Hospital. Vitamin D is also derived from the sun. "Vitamin D is formed underneath our skin when exposed to sunlight rich in UVB. We see a deficiency in cities with thick pollution cover or in individuals who have a lifestyle which involves only indoor activities,” says Dr Archik.

What does a Vitamin D deficiency look like?

Studies have also found a correlation between Vitamin D deficiency and mood swings, irritability, depression, impaired blood sugar control and anxiety. Signs of deficiency include fatigue, low back pain, and muscular pain and muscle cramps. Older people are prone to fractures while children see recurrent chest infections. “It can lead to weaker bones, rickets, tiredness, back pain and hair loss,” says Dr Archik. “Prolonged breastfeeding, and heavy skin pigmentation reduces the synthesis of Vitamin D in the skin,” adds Shaikh, which means that Indian skin is less likely to soak it in—melanin is the substance in skin that adds colour, and it competes for UVB rays.

While exposing yourself to sunlight in the morning is ideal, supplementation and getting Vitamin D from food is just as important. “As prophylaxis, children can take a dosage of 1000IU/day while adults can take 2000IU/day,” says Shaikh. Still, it is best not to self-medicate, as too much Vitamin D can cause hyper-toxicity. Instead, look to food sources. “Cod liver oil, shrimp, lamb liver, mackerel, egg yolk and canned tuna are great. A recent study showed that tomato plant leaves are a great source too,” she says.

Also read:

The supplements and healthcare tests recommended for women in their 20s, 30s, 40s and 50s

The only health supplements you need to take based on your age

Coronavirus outbreak: A doctor debunks 6 of the biggest myths