It is the acute vitamin D deficiency. Sun is the best source of vitamin D for humans along with other foods and nutrients that it provides our body.  

Since we all are mostly home-bound, our exposure to the outside world and the sun has decreased drastically. Although the levels of vitamin D were low in many people even before the lockdown, the work from home restriction has only made it worse.  A medical expert said:

People should try and expose themselves to sunlight every day for at least 20 minutes in the morning. The vitamin can also be had from foods like fish liver oil and fishes like salmon and tuna. For vegetarians, leafy vegetables, particularly sundried, will help.

Vitamin D is known to help regulate the amount of calcium and phosphate in the body. These nutrients are needed to keep bones, teeth and muscles healthy. A lack of vitamin D can lead to bone deficiencies and deformities like rickets in children, and bone pain caused by a condition called osteomalacia in adults.  

In relation to Covid-19, studies show that vitamin D boosts immunity and helps fight infections. Researchers associated with Northwestern University and Boston Medical Centre believe that while vitamin D is good for a healthy body, it also helps in controlling and fighting the complications caused by viruses.

Though it is important for us to stay home, we need to take more care of our health and body. This can be by exposing ourselves to the sun for at least 20 minutes each day. May it be from your balcony or the garden, spending some time in the sun will prove to be beneficial.