In search of Vitamin D this summer of lockdown

Updated - April 08, 2020 11:44 pm IST

Published - April 08, 2020 11:40 pm IST

Dr. V. Mohan, Senior diabetologist

Dr. V. Mohan, Senior diabetologist

As spring turns to summer, the nation is for the first time looking forward to the heat as it is widely believed that the novel coronavirus (COVID 19) will not be able to survive the hot Indian summer, where, in some places, the soaring mercury can make it very difficult even for us mere mortals to survive. However, this hypothesis still needs to be proven, as with most things regarding COVID-19 are still shrouded in mystery.

But there is another reason to welcome the Indian summer. It is that time when we get an opportunity of being exposed to sunlight to obtain our requisite dose of Vitamin D. Sadly, despite India being a tropical country, most Indians (over 60% as shown in a recent study done by my team) are deficient in (< 20 ng/ml) or have insufficient (20-30 ng/ml) Vitamin D. Even the recommended dietary allowance of Vitamin D (400-800 IU) is arguably very low for Indians who probably need between 2,000 and 4,000 units of Vitamin D a day to maintain normal blood levels of the vitamin.

Diet alone does not seem to be enough, for several reasons. First, we do not eat the right food in adequate amounts, processing of food over the years has reduced its micronutrient content, and sometimes our cooking practices (excessive cooking) might contribute to this national Vitamin D insufficiency. Added to this, many of us live or work within the air-conditioned environment at our home and in offices. Our dark skin (melanin) and the clothes we wear may make it difficult for our skin to get enough vitamin D from the sun.

A micronutrient is required in small or micro quantities and yet we Indians are deficient in micronutrients, which can lead to macro consequences as micronutrients are co-factors for the efficient catalytic action of many enzymes in our body, and they enable us to optimally use our macronutrients as well.

Benefits of walking

We do not go for walk when we should (10 a.m. to 3 p.m. is the best time for optimal sunlight of a particular wavelength, UV-B, 290-320 nm to reach our skin) and some of us apply sun screen lotions with sun protection factor (SPF) that again impairs production of adequate vitamin D precursor in the skin.

So, what has all this to do with COVID-19? COVID-19 has understandably led to a lockdown in our country for 21 days till April 14 to break the chain of transmission and flatten the epidemic curve. And even after that we will need to stay at home as far as possible, practise social distancing, and adhere to personal and public hygiene standards. In such a situation, exposure to the sun will further go down. Hence, it may be worthwhile to consult our doctors, test our Vitamin D levels, and if deficient or insufficient, then we must supplement our diet with vitamin D to meet our body’s needs.

You would be interested to know that Vitamin D is not just a vitamin or micronutrient. It is also a hormone in that it has effects way beyond the well-known effects on bone mineral metabolism. Incidentally, the bone is an endocrine organ. There are Vitamin D receptors on many cells in our body and at a genetic level, Vitamin D modulates cell function. It may be an uncanny coincidence, but there is evidence to suggest that Vitamin D may have some anti-coronavirus activity as well (e.g., it attenuates the Spike protein of this virus which is an obvious advantage). Moreover, it has the potential to modulate the cytokine storm seen in serious COVID-19 patients, and it can improve innate immunity by increasing the production of cathelicidins and defensins in our body.

But the more important point is that if we are deficient in Vitamin D, then we need to take steps to detect and then treat this problem. The prevalence of Vitamin D deficiency is higher in people with diabetes. Hence, as people with diabetes are known to have a more severe form of COVID-19 infection, they should particularly pay attention to improving their Vitamin D levels. Vitamin D can strengthen our immune system and our ability to stay strong and healthy. On a lighter note, one of the simple approaches to COVID-19 could be COVID – Co rrecting V itamin D I nsufficiency and D eficiency!

Your doctor will tell you whether you need to take Vitamin D and if yes, at what dose. Remember that it should never be taken without the advice of a doctor. All medicines, including vitamins, are double-edged swords and their indiscriminate use can lead to side-effects and even toxicity.

Just as personal protective equipment (PPE) are life-saving for health-care workers in hospitals treating serious COVID-19 patients, for patients with chronic conditions, such as those with diabetes or hypertension, their doctors are their PPE. Hence these patients should stick to their doctors’ advice on lifestyle modification, take the prescribed medicines prescribed on time, and check their BP, blood sugar level and so on to try and be at goal so that they are better equipped to face the ravages of COVID-19, just like people without these conditions.

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