The correct answer is b) synthesis of vitamin E.
The skin performs several important functions for the body, including:
- Regulation of body temperature: The skin helps regulate body temperature through sweat production and blood flow to the skin.
- Defense against disease organisms: The skin acts as a barrier, protecting against pathogens and harmful substances.
- Excretion of water and salts: Sweat glands in the skin help excrete excess water and salts from the body.
However, the synthesis of vitamin E is primarily not a function of the skin. Vitamin E is obtained mainly through dietary sources and is not produced by the skin, unlike vitamin D, which the skin synthesizes when exposed to sunlight.