Kathmandu. Vitamin D is one of the essential nutrients for the body, it plays an important role in keeping bones strong and in the body's use of calcium.But vitamin D deficiency is seen in most people. This problem is found in every second person. This may be due to not staying in sunlight for enough time.Due to lack of time or fear of skin tanning, most people do not stay in contact with the sun for a long time these days. They go inside after staying in the sun for 5 to 10 minutes, but this alone is not enough....