Effect of micronutrient-fortified milk on zinc intake and plasma concentration in adolescent girls.

To assess the effect of dietary fortified milk with zinc and other micronutrients on zinc intake and plasma zinc content of adolescent girls. The study included 108 schoolgirls (12-18 years old) from northwest Mexico, randomly assigned to either the control group (CG; n = 55) or the intervention group consuming a regular diet plus fortified milk (MG; n = 53). At the beginning of the study, age, weight, and height were measured. Food intake by the 24-hour recall method and plasma zinc levels assessed by absorption spectrophotometry were determined before and after 27 days of fortified milk intake. At baseline, no significant group-related differences were observed for energy, protein intake, zinc intake, and plasma zinc level (p > 0.05), and 35.2% of participant girls did not achieve their zinc requirement. After 27 days of treatment, there were no significant differences in energy and protein intake between groups (p > 0.05). Zinc intake was higher for MG than CG (16.7 ± 8.3 mg/d vs 10.5 ± 6.4 mg/d; p < 0.01), and there was a lower proportion of low zinc intake in MG than for CG (7 vs 16, respectively; p = 0.04). In addition, plasma zinc improved in the MG (116.6 ± 26.9 μg/dL, p < 0.01) compared with CG (98.5 ± 26.6 μg/dL), and it was mainly attributed to the fortified milk intake, as the main dietary zinc contributor. Fortified milk intake is effective in increasing both intake and plasma zinc levels of adolescent Mexican girls; therefore, it could be an adequate strategy for zinc deficiency prevention or correction among adolescent girls.