When it comes to the how vitamin D bienfets the life and health of a person in several more ways than is commonly known. The sunshine' vitamin, as it is sometimes called, is commonly known for its effect on strengthening the bones and joints in the human body by aiding the absorption of calcium. It also helps the body build up immunity. Our bodies can produce vitamin D organically, if we have sufficient amounts of sun (at least an hour a week). Alternatively, it wouldn't be uncommon for it to be added to certain foods such as milk, egg yolks, fatty fish, sardines, mackerel, tuna and salmon. These vitamin d rich foods are known to be a plentiful source of omega 3 fatty acids. Cod liver oil capsules are one of the most popular nutrient and Vitamin D dense supplements. I've found that adequate vitamin D levels are absolutely essential for a healthy life. I hope that is helpful to you.