We all know that sunlight can help our body generate vitamin D which a vital nutrient to ward off asthma and Parkinson's diseases later in life. A 60-year study by US researchers finds that vitamin D added to an asthma action plan may improve asthma control. A 30-year by Finland's National Institute for Health and Welfare finds that lack of vitamin D in the body can lead to Parkinson's disease later in life.

Lack of Vitamin D can lead to lower lung functions which mean lesser asthma control when it strikes. It also plays a vital role in strengthening our nerve cells, which gets affected in Parkinson's disease. Most vitamin D is made by the body when the skin is exposed to sunlight, although some comes from foods like oily fish, milk or cereals. It plays a major role in regulating our immune system as well as in the development of the nervous system.

However, researchers are still working on finding out the optimal level for brain health or at what point vitamin D becomes toxic for humans. Experts suggest getting vitamin D through diet and little sunlight exposure. They are still wary of taking it as a supplement since studies of its efficacy is still being tested.