[Bioefficacy of plant carotenoid to vitamin A in school age children].

OBJECTIVE

To determine the bioefficacy of pure beta-carotene and beta-carotene from spinach to vitamin A in schoolchildren of different vitamin A status.

METHODS

Thirty two schoolchildren aged 7-9 years old were selected and then divided into two groups randomly. Each group included 16 subjects, of which the vitamin A level of 8 subjects was normal, the other 8 subjects suffered from vitamin A deficiency. In the first 7 days, one group was given 5 gram spinach (containing 230 microg 2H10-beta-carotene) before lunch and dinner and the other group was given pure beta-carotene capsule (containing 200 microg beta-carotene). Before breakfast, both groups were given 100 microg 13C10 retinal acetate capsule. Blood was drawn on the 3, 7, 8, 22 and 28 day. HPLC and GC-MS were used to determine the retinol concentration and enrichment of isotope and then calculate the bioefficacy of pure beta-carotene and beta-carotene from spinach to vitamin A.

RESULTS

The conversion factors of pure beta-carotene to vitamin A in oil capsule were: 2.9:1 for the children with normal vitamin A status, 3.2:1 for those suffering from marginal vitamin A deficiency. The conversion factors of spinach beta-carotene to vitamin A were 10.1:1 and 10.3:1 for the children with normal and low vitamin A status, respectively.

CONCLUSION

The vitamin A conversion bioefficacy of pure beta-carotene from oil capsule is much higher than that of spinach. There is no difference of beta-carotene bioefficacy to vitamin A for children with different vitamin A status.