Selenium is a nutrient that helps your body is a variety of ways. It is important for fighting free radicals and infections, repairing DNA, thyroid gland function and metabolism. It is critical to fertility and reproduction, and is suggested to reduce the chance of a miscarriage. 

Vitamin A (retinol) is essential for good eyesight and extremely helpful in preserving our skin, joints, eyes and internal organs. If there really was a Fountain of Youth, retinol would be one of the key ingredients and it would probably be reddish-orange due to the beta-Carotene. The body converts the red-orange pigment into Vitamin A. It also supports the immune system, bone metabolism, and development of embryos in reproduction. It is an antioxidant vitamin, which destroys free radicals in our body. Free radicals are produced by the body when we smoke, don’t eat a proper diet, or are exposed to stress or pollution. They are also suspected of contributing to cancer and cardiovascular disease. Pregnant women who are deficient in Vitamin A are more likely to have premature birth or very low birth weight. Women who have high levels of Vitamin A have a lower risk for breast cancer.

Vitamin A is made by your body when you eat carrots and other yellow and orange fruits and vegetables which contain beta-carotene, such as sweet potatoes, pumpkin, cantaloupe, papaya, peas, butternut squash, mango, and dried apricots. It is also found in spinach, kale, collard greens, broccoli, tomato juice, peppers, watercress and full fat dairy products (butter, milk, eggs, cheddar cheese). Interestingly enough, these are ready to eat raw and cooking them causes the loss of some of the vitamins. Liver, beef, chicken, turkey, and fish are also high in Vitamin A content. 

Vitamin C (absorbic acid) is found in many natural fruits and vegetables such as green leaf vegetables, broccoli, green peppers, carrots, bean sprouts, tomatoes, mango, papayas, strawberries, lemons, limes, and other citrus fruits.
 
Your body requires Vitamin C in order to produce collagen, which is found in your skin, bones, cartilage, ligaments, tendons, and blood vessels. It also serves as a detoxifier to reduce toxic chemicals from your body. Without Vitamin C, people are susceptible to many diseases from the common cold to scurvy, which will result in death if it is not treated. Eating fruits and vegetables helps your body grow and repair and even prevents signs of aging by helping to keep skin firm. 

Vitamin D helps keep your bones healthy by helping your body absorb the calcium in your diet. It helps prevent rickets in children. 
 
Fish and egg yolks are two of the few natural foods containing Vitamin D, however eating these is not enough. In order for the body to use the vitamin, it requires the help of the sun. The sun turns chemicals in your skin into Vitamin D3, which is carried to your liver and kidneys, where it is transformed into active Vitamin D.