Significance of postprandial blood concentrations of retinol, retinol-binding protein, and carotenoids when assessing the vitamin A status of children

Abstract

The effect of ingesting a breakfast rich in vitamin A on postprandial blood serum concentration of retinol, retinol-binding protein, and carotenoids has been investigated in children between 5 and 8 yr of age. They were divided by age in two groups (5 to 6 and 7 to 8 yr) and then randomly assigned in three groups to be studied cross-sectionally immediately before and at 2 and 4 h after the ingestion of a meal containing 337 micrograms of retinol equivalents (48% as retinol and 52% as carotenoids). The ingestion of breakfast did not alter significantly (p greater than 0.05) the postprandial serum concentrations of retinol, retinol-binding protein; or carotenoids in any of the age groups. These results indicate that up to 4 h the postprandial blood serum concentrations of these parameters are representative of their corresponding basal concentrations. Therefore, in practice and particularly under field survey conditions, the blood samples required to assess the vitamin A status of children can be obtained either fasting or within 4 h after breakfast without altering the results.

Serum concentrations of retinol and retinyl esters in adults in response to mixed vitamin A and carotenoid containing meals.

“…In two reported studies which included young adults (ages not given), as well as children (5-8 years old), no significant rises in total serum vitamin A levels (measured spectrophotometrically) were seen up to 4 hours after subjects consumed up to 67% of the RDA in a vitamin A-carotene mixed meal [1,2]. This method measured both retinol and retinyl esters together.…”

“…Studies among 5-8-year-old children and young adults fed mixed vitamin A and carotene containing meals have shown that previous food intake has no effect on serum vitamin A levels up to 4 hours postprandially [1,2]. The authors of these studies concluded that for young subjects fasting blood for vitamin A analysis is unnecessary when assessing vitamin A status.…”

Perinatal Plasma Carotenoids and Vitamin E Concentrations with Glycemia and Insulin Resistance in Women during and after Pregnancy

“…However, studies have shown stability in carotenoid and αand γ-tocopherol concentrations from the second trimester to delivery [42,43] as well as stability in dietary patterns throughout pregnancy [44,45]. The use of non-fasting plasma samples may have introduced systematic bias, but studies have shown non-significant differences in carotenoid concentrations pre-and post-meal [46,47]; the effect of fasting compared with non-fasting is less clear for plasma E vitamers due to limited literature. Findings regarding the gestational HOMA-IR were also limited by the smaller sample size, as more than half of the cohort did not provide sufficient fasting blood samples for insulin measurements.…”