Vitamin B2 (Riboflavin)

What it does

Vitamin B2, or riboflavin, is central to energy production. It forms two coenzymes — FAD and FMN — that carry electrons through the chemical reactions the body uses to release energy from fats, carbohydrates and proteins. In this sense riboflavin is a workhorse of metabolism, involved wherever cells are converting food into the energy currency (ATP) that powers everything they do.

Riboflavin also plays a protective, "recycling" role for the body's antioxidant defences. It is needed to regenerate glutathione, one of the body's most important antioxidants, which helps limit the damage done by reactive molecules produced during normal metabolism. It further supports the activation of other B vitamins, including vitamin B6 and folate, so a shortfall in riboflavin can quietly disrupt several other nutrient pathways.

It keeps skin, eyes and the linings of the mouth healthy, which is why deficiency tends to show up as cracks at the corners of the mouth, a sore tongue and sensitive eyes. Good sources include milk and dairy, eggs, lean meat, and fortified cereals. Riboflavin is sensitive to light — which is one reason milk is no longer sold in clear glass bottles left out in daylight — but it stands up well to heat and cooking.