Zinc and copper content of foods used in vegetarian diets.

The zinc and copper content of seventy-four foods was determined by atomic absorption spectrophotometry. Each of these foods was reported to have been consumed by practicing vegetarians. Legumes, seeds, nuts, whole grains, hard cheeses, and some nutritional supplements were found to be excellent sources of both zinc and copper. Vegetables, fruits, and their products were generally poor sources of trace minerals, with the exception of seed and bean sprouts. Milk and milk products, including rennetless cheeses, contain small quantities of these minerals. Although many of the foods consumed by vegetarians do contain adequate amounts of zinc and copper, their bioavailability may be limited.

Zinc status of vegetarians.

The zinc status of seventy-nine vegetarians and forty-one non-vegetarians was investigated. The subjects provided 24-hr. dietary recalls and donated samples of blood, hair, and saliva that were subsequently analyzed for zinc content. Avoidance of animal products in the diet was associated with decreased intakes of energy, protein, fat, calcium, and zinc and increased consumption of crude fiber, potassium, vitamin A, and ascorbic acid. The low dietary intake of zinc by vegetarian women was believed to result from liberal use of foods low in zinc such as fruits and vegetables, whereas vegetarian men primarily consumed zinc-rich food such as legumes and cheeses Lacto-ovo-vegetarians consumed twice the amount of crude fiber consumed by non-vegetarians and vegans four times as much. The zinc content of salivary sediment was significantly lower in vegetarians than in non-vegetarians; vegans had the lowest mean level. The observed decrease in salivary zinc was inversely proportional to the amount of crude fiber in the diet. Zinc levels in the hair of vegetarians were significantly lower than those in the hair of non-vegetarians, while serum levels were also lower, but not significantly so. The increased crude fiber intake of vegetarians coupled with the decreased levels of zinc found in saliva and hair seem to indicate that some vegetarians, particularly women, have less than satisfactory zinc status.