Nearly 17% of worldâs population is at risk of zinc (Zn) deficiency. Introducing practices to improve intake, absorption, and utilization of micronutrients from diets can be an effective approach to combat this problem. We aimed to evaluate whether milk consumed with phytate-rich rice can improve the absorption of Zn.
Two absorption studies were conducted using a cross-over design with 1-month washout. Rice Study: 18 subjects received 90g of intrinsically 67Zn labelled rice with 600mL of water or milk; Milk Study: 19 subjects received 800mL of either UHT milk, UHT milk diluted 1:1 with water, water or raw milk; extrinsically labelled with 67Zn. All treatments within a study provided similar amounts of total Zn. An intravenous infusion dose of 0.02mg 70Zn in saline was given half-way each meal. Fractional absorption of zinc (FAZ) was calculated from the isotope ratios. Additionally, we assessed Zn extraction from rice blended with water, raw milk, or UHT milk with or without phytate in vitro.
FAZ from UHT milk and raw milk was similar. FAZ from rice with milk (21.7%) was significantly higher than with water (13.4%; P<0.001). In vitro, UHT and raw milk also showed a significantly higher Zn extraction from rice compared to water at various phytate concentrations.
Milk consumed with a phytate-rich meal enhanced Zn solubility in vitro, and increased FAZ from rice by 62%. Further population studies are needed to underscore the role of milk in combatting Zn deficiency.