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 micromol/g, respectively. Liver vitamin A concentrations on day 18 were 0.069+/-0.004, 0.14+/-0.044, and 0.11+/-0.026 micromol/g in the control, low-dose, 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 micromol/L) than at late kill (0.76+/-0.24 micromol/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 improving infant vitamin A status.