Possible Interaction: Carotene and Vitamin A

“The in vivo conversion of carotene to vitamin A was found to vary from 20 to 80 per cent depending on the nutritional status.”

“In stratified analysis by sex, the significant inverse associations for β‐carotene and retinol were observed only in men and not in women.”

“This case–control study explored the associations between the dietary intake of VA and carotenes and the risk of PLC.”

“The treatment of cells with βcarotene up to 30 M for 72 h led to a significant increase in the cellular βcarotene concentration and formation of retinol.”

“ Serum carotene level correlated significantly with that of retinol , and their coefficient of correlation was greater in the winter than in the autumn.”

“This study offers evidence that heritability and the reduced conversion of carotene may play a role in the level of serum retinol in type 1 diabetes cases.”

“Intake … carotene … vitamin A was inversely associated with cataract: in multivariate analyses, women in the highest fifth of total vitamin A intake (excluding supplements) had a 39% … risk of cataract relative to women in the lowest fifth (relative risk 0.61; 95% confidence interval 0.45 to 0.81).”

“Inasmuch as a difference in risk associated with retinol and carotene has been shown in a few previous inquiries dealing with esophageal cancer and cancer at other sites, a need for further investigations distinguishing risks associated with the two compounds is apparent.”

“High carotene levels may thus give spuriously high vitamin A values unless corrected for.”

“In normal individuals there was a highly significant correlation between serum concentrations of vitamin A and carotene (rs=0.606, P smaller than 0.001), whereas in patients with CF this relationship was less significant (rs=0.311, P smaller than 0.02).”