Genetic background contributions to the disproportion of vitamin A deficiency in pregnant women of certain ethnicities in populations of the United States.

Vitamin A is an essential micronutrient that plays critical roles in many biological functions of the body. Limited access to vitamin A-rich food or supplements severely affects tissue and blood levels of vitamin A. Therefore, low serum vitamin A and poverty levels are strongly associated in vitamin A deficiency (VAD) studies that have focused mainly on developing countries. The current national prevalence rate of vitamin A deficiency in the United States is reported to be very low (< 1%). However, several studies, including ours, have suggested that people from certain ethnic groups still face a higher proportion of vitamin A deficiency. Here, we re-analyzed two different datasets of serum retinol levels of pregnant females to assess the VAD status differences between women of different ancestries. We found that pregnant females with non-Hispanic Black and with Latin American/Afro-Caribbean ancestry have strikingly high proportions of vitamin A deficiency. Moreover, we identified candidate genetic variants that associate with the disproportions between these different ancestries. Maternal vitamin A deficiency increases the risk of adverse health outcomes for both the mother and offspring later in life. Measuring serum retinol levels of pregnant women in the higher risk groups and provision of food interventions based on genetic information to improve the vitamin A status of at-risk women are needed. Our study strongly suggests that emergency actions need to be taken to reduce vitamin A deficiency in specific, at-risk ethnic groups.