Serum retinol is associated with stage of pregnancy and the acute phase response in pregnant women in Guinea-Bissau.

Vitamin A deficiencies in pregnancy may impair the health of the mother and the growth, development, and later health of her offspring. However, the understanding of the variability of micronutrient status markers during pregnancy is limited. We measured serum retinol and β-carotene and the acute phase proteins C-reactive protein (CRP) and α(1)-antichymotrypsin (ACT) in 738 pregnant women in a cross-sectional study in Guinea-Bissau, West Africa. Gestational age ranged from 7 to 42 wk (mean ± SD = 23 ± 7 wk). The serum retinol concentration was 1.03 ± 0.33 μmol/L (mean ± SD) whereas serum β-carotene was 1.40 (0.85, 2.13) μmol/L [median (25, 75 percentile)]. Vitamin A deficiency (serum retinol <0.70 μmol/L) was observed in 13.8% of individuals. Serum CRP was elevated (>3 mg/L) in 51.6% of individuals and ACT (>0.3 g/L) in 66.3%. Gestational age >20 wk (β = -0.11; P < 0.001) as well as elevated serum CRP (β = -0.16; P < 0.001) and ACT (β = -0.80; P = 0.004) were associated with lower serum retinol. Based on this large cross-sectional study, we suggest that serum retinol and its conventional cutoff may be underestimating the vitamin A status in late pregnancy and in populations with high prevalence of infections. However, prospective cohort studies measuring the serum concentration of retinol during and after pregnancy and inflammation are needed to describe the physiological behavior of serum retinol and thereby to improve the assessment of vitamin A status.