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 is a fat-soluble vitamin with known toxicity. Although its toxicity has been exaggerated, it is a factor worth keeping in mind. Carotine is converted in the human body to Vitamin A, it comes from vegetable sources. Vitamin A is necessary for normal growth and for skeletal development.

Vitamin C is an obvious essential nutrient and a deficiency of this will cause scurvy. It is also an antioxidant and acts as an electron donor for eight different enzymes.