Evelyn on NaturallyCurly writes:
Vitamin D facilitates skeletal growth and strength, working with calcium and phosphorus to be absorbed better. It also strengthens your immune system by increasing the activity of “natural killer cells.”
You can get this vitamin by eating fatty fish (catfish, salmon, mackerel, sardines, tuna) eggs, and meat. In more developed countries, staple foods such as milk, flour, and margarine are artificially fortified with vitamin D. Mushrooms are the only vegan/vegetarian food source of vitamin D.