Calcium, a mineral vital to the human body, Calcium is necessary for many bodily functions, such as muscle contraction, and proper heart function.

Iron is a necessary mineral for humans, needed for example to help form red blood cells which transport oxygen around the body. Fortunately there are plenty of good sources available for both the omnivore and the vegetarian or vegan These include liver, meat, beans, nuts, dried fruit , also whole grains and many of dark green leafy vegetables, although some such as spinach also contain substances that prevent the absorption of iron as do caffeine based drinks such as tea and coffee. On the other hand the drinking of fluids containing vitamin C aids the body in its necessary task of absorbing iron.

Vitamin A- Otherwise known as retinol is the vitamin which helps the eyes to adjust to changes in light levels as well as keeping the eyes, skin and mucous membranes moist. Vitamin A enters the human diet mostly from animal foods, but as well as this some plant foods contain beta-carotene, which the body is then able to convert into Vitamin A. Retinol has antioxidant properties that help the body to repair tissue and cellular damage by neutralizing free radicals. Although there seems to be some evidence that retinol may help in cases of established artery disease the American Heart Association does not recommend it as a necessary supplement until there is more evidence.

Vitamin C is well known for its powerful ability to help boost the immune system as well as fight off damage causing free radicals. As an anti-oxidant, vitamin c binds with free radicals, preventing them from damaging cells. This damage can cause early aging and even has been linked to some cancers. By taking vitamin C supplements, you are helping prevent these free-radicals, as well as giving your immune system a boost as well. Vitamin C is integral to cellular metabolism as well and a lack of vitamin C can cause a myriad of issues, including scurvy.