Iron is one of the most commonly available chemical elements which are used in the form of metal. When in the presence of oxygen and moisture, iron gets oxidized very easily. Therefore it is never available on the surface of earth. Iron is a metal whose properties can be changed by mixing it with the various other metals. Humans need iron as a daily dietary substance. There are a number of supplements available in market which provides the daily required dose of iron. But the best way to consume iron is by eating the food that is rich in iron. Fish, poultry, beans, lentils, leafy vegetables are some of food items that are a good source of iron. Although, research shows that it is easier to digest the iron found in meat and meat products than the vegetables.

Magnesium, which is a mineral used by the body to help maintain muscles, bones, and nerves. Magnesium is also needed for energy metabolism and protein synthesis.

Vitamin A is a vitamin is needed by the retina of our eye in the form of a specific metabolite, the light-absorbing molecule retinal. This molecule is absolutely necessary for both scotopic and color vision. It also palys an important role in mainating body health, such as skin health, bone metabolism and immune function. Vitamin A is also commercially produced and administered as esters such as retinyl acetate commonly called Vitamin A acetate. Its defeciency can cause blindness. Some other problems include impaired immunity, keratosis pilaris and squamous metaplasia of the epithelium lining the upper respiratory passages and urinary bladder to a keratinized epithelium.

Vitamin C, also known as Ascorbic (a-SKOR-bik) acid, is needed for many functions in the body, including helping the body use carbohydrates, protein, and fats. Vitamin C is found in most citrus fruits and green vegetables and is a strong antioxidant.