J Am Diet Assoc. 1980 Dec; 77(6): 655-61.
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.