As this vitamin is one of the necessary vitamin for our body .
This deficiency is usually because of lack of sun and sunshine . For this you should change your daily routine have some sun bath .
Many of experts recommend to sit in the sun daily for min 10-15 min
Now the question is that HOW OUR BODY GET VITAMIN D FROM SUN???
So for this their is a substance name Melanin , Its present in our skin.The amount of melanin in our skin will effect the amount of vitamin D you can produce ; SO the fairer the skin tone the more you can make vitamin D or vice versa.
The more sunshine we receive the melanin is released in our skin.Its about 90 - 95% Vitamin D comes from sunshine.
You can also use following food :