Calcium
This is required for nerve and muscle functions and blood clotting. In addition it can help with the formation and maintenance of healthy bones and teeth. Calcium supplements have also been found to help with osteoporosis patients, post-menopausal women (1.5g per day) and pre-menopausal women (1g per day).

Iron
If you do not eat enough red meat it is likely that you will have low iron stores, and if this continues you may go on to show signs of iron deficiency anaemia. Iron is essential for red blood cell development (in the pigment haemoglobin) and for the production of energy in the body. Teenage girls who had low iron levels and then took iron supplements were shown to improve their learning abilities.

Selenium
This is a component of an antioxidant enzyme that that helps to protect body cells. It is important for the health of your liver and heart. Selenium has also been shown to help with cancer prevention when taken in a daily supplement of 200mcg.

Zinc
Zinc is needed for enzyme production, cell division, growth, reproduction, a healthy immune system, and the perception of taste and smell. Zinc supplements are also believed to help men with benign prostate disease, as they appears to inhibit the production of the hormone involved in the enlargement of the prostate gland.