Vitamin A: 1 It is the raw material for synthesizing retinaldehyde. 2. It is an antioxidant in the body. 3. Vitamin A and its derivatives can inhibit the growth of tumor. The most typical symptom of vitamin A deficiency is night blindness. Food comes from the livers of mammals and saltwater fish.

Vitamin C: 1. It is a coenzyme of some hydroxylases. 2. Participate in redox reaction in vivo as an oxidant. 3. Enhance the body's immunity.

Vitamin c deficiency can lead to scurvy. Vitamin C is widely found in fresh vegetables and fruits.

Vitamin D: 1. Regulate blood calcium level. 2. Affect cell differentiation. Lack of children will lead to rickets, and lack of adults will lead to rickets. Food sources include fish oil, egg yolk and liver.

Vitamin E: 1. It is the most important fat-soluble antioxidant in the body. 2. Regulate gene expression. 3. Promote the synthesis of heme.

Vitamin e deficiency can lead to mild anemia. Food sources are vegetable oil, oil-bearing seeds and malt.