Zinc intake and sources in the US adult population: 1976-1980

To determine levels of intake and food sources of zinc in 1976-80 in US adults between the ages of 19 and 74.

Dietary data from 24-hour recalls collected in the Second National Health and Nutrition Examination Survey were analyzed. Levels of zinc intake were compared between demographic subgroups using analysis of variance. The contribution of individual foods to overall zinc consumed was also estimated.

Mean daily intakes (+/- SEM) were 15.5 mg +/- 0.4 and 9.8 mg +/- 0.2 in white men and women, respectively. Mean daily intake estimates in black men and women (12.3 mg +/- 0.8 and 7.8 mg +/- 0.3, respectively) were significantly lower. Lower intakes were observed in women versus men, in older (65 to 74 years) versus younger (19 to 34 years) age groups, and among people with lower versus higher education and income levels. Lower zinc intakes in women and older persons could be mainly attributed to lower overall energy intake compared with gender and age counterparts. However, lower intakes in blacks and persons with lower education or income levels were not explained by differences in energy intake and may be attributed to differences in food selections. Meat and milk products contributed the majority of zinc in recalled diets, accounting for 56 and 60% of total zinc intake in blacks and whites, respectively.

Levels and sources of zinc intake in 1976-80 were higher than in more recent national surveys, suggesting that zinc intakes may be declining. Population groups more likely to have lower intakes were women, older adults, blacks, and those with lower levels of education and higher poverty levels.