One-time vitamin A supplementation of lactating sows enhances hepatic retinol in their offspring independent of dose size

Background: Single megadoses of vitamin A between 200 000 and 400 000 IU have been administered to lactating mothers to improve the vitamin A status of both mothers and breastfeeding infants. However, the most beneficial dosing regimen is not known. Objective: The effect of megadoses of vitamin A supplements given to lactating sows on hepatic vitamin A concentrations in their nursing offspring was examined. Design: Lactating sows were given a high (2.1 mmol), low (1.05 mmol), or control (0 mmol) dose of retinyl acetate in oil (n = 3 sows per treatment). Piglets nursed for 3 or 14 d, consumed a vitamin A-free diet for the next 4 d, and were then killed. Liver and serum samples were analyzed for vitamin A. Results: After 3 d, piglets of the control, low-dose, and high-dose sows had different (P = 0.034) hepatic vitamin A concentrations, ie, 0.078 ± 0.004, 0.14 ± 0.053, and 0.13 ± 0.026 μ,mol/g respectively. Liver vitamin A concentrations on day 18 were 0.069 ± 0.004, 0.14 ± 0.044, and 0.11 ± 0.026 μmol/g in the control, lowdose, and high-dose piglets, respectively (P = 0.017). Liver vitamin A concentrations in piglets of the low- and high-dose sows were not significantly different (day 3: P = 0.97; day 18: P = 0.59). Serum retinol concentrations were higher (P = 0.02) at early kill (0.95 ± 0.22 μmol/L) than at late kill (0.76 ± 0.24 μmol/L) but were not significantly different between groups. Conclusions: Maternal vitamin A supplementation enhances liver vitamin A concentrations in offspring. Larger one-time doses are not more effective than are smaller doses. Additional research is needed to determine the most effective maternal dosing regimens for imroving infant vitamin A status.