The overall objective is to determine the impact of EED on zinc absorption and homeostasis, and its impact on the absorptive capacity of vitamin A absorption of young children (18-24 months of age) in an austere setting with high rates of diarrhea, stunting, and micro-nutrient deficiencies.

Participating children are screened for EED using the lactulose:mannitol ratio test and assigned to one of two groups: +EED or -EED. All participants will be given standard, physiological dose of 3 mg zinc sulfate with a zinc stable isotope tracer on study day 8.

On study day 11, 0.5 mg of 13C10-retinyl-acetate will be administered orally to all participants.

Spot urine samples will be collected twice daily from study days 11-14. Complete fecal collections will be obtained for days 11-14. Duplicate diets of all foods consumed will be collected on days 11-14. On study day 14, a blood sample will be taken for analysis of vitamin A isotope status.

Inclusion Criteria:

• Absence of apparent health problems that would impair ability to consume regular diet, to tolerate zinc supplements, or to comply with demands of metabolic studies
• Length for age Z-score (LAZ) between -1.5 to -3.0
• Hemoglobin (Hgb) ≥ 8

Exclusion Criteria:

• Outside age range
• Hgb < 8
• Chronic illness
• Recent diarrhea (within past 2 weeks, treated with supplemental zinc)
• Severe stunting and/or severe acute malnutrition (SAM): LAZ <-3; Weight-for-age Z-score (WHZ) <-3 or mid-upper arm circumference (MUAC) < 115 or edema

Toddlers aged 18-24 mos living in Dhaka, Bangladesh