Sunlight is the best source of Vitamin D. When the skin is exposed to sunlight, our body converts cholesterol to the D Vitamin. Apart from the sunrays, a few foods can also provide you with this nutrient. Oily fish, cod liver oil, red meat, fortified cereals, fortified spreads and egg yolks, spinach, kale, okra, soybeans. You can also take Vitamin D supplements after consulting your doctor to increase the intake of this vitamin.