An Institute of Medicine (IOM) report released on Tuesday (9 January), says strict vegetarians should consider increasing the amount of dark-coloured vegetables in their diets in order to avoid deficiencies in vitamin A and iron. The IOM  adjusts national recommended levels of vitamin A and several other nutrients.

The report detailed adjustments to the recommended dietary allowance (RDA) of vitamin A set in 1989. New recommended levels are 900 micrograms per day for men and 700 micrograms per day for women. Twelve micrograms of beta-carotene equals 1 microgram of vitamin A in the body. The panel also changed its recommendations for daily iron intake to 8 milligrams (mg) per day for men and postmenopausal women and 18 mg per day for premenopausal women.

The panel revealed that vegetables such as carrots, broccoli and sweet potatoes, usually relied upon to provide vitamin A, only deliver to the body half the amount of usable nutrient as previously thought.  Vitamin A can however be found in other foods including animal products like dairy.

Importantly, vegetarians who avoid animal products altogether should be careful to get enough dark fruits and vegetables high in carotenoids, the metabolic precursors to vitamin A, to guarantee optimal vision and lower the risk of birth defects, according to Dr. Robert Russell, chairman of the IOM panel on micronutrients.

The report also examines the nutritional value of the micronutrients vitamin K, arsenic, boron, chromium, copper, iodine, manganese, molybdenum, nickel, silicon, vanadium, and zinc.