Vitamin A status and its relationship with serum zinc concentrations among pregnant women who have previously undergone Roux-en-Y gastric bypass

Abstract

Objective: To evaluate vitamin A status and its relationship with serum zinc concentrations among pregnant women who had previously undergone Roux-en-Y gastric bypass (RYGB), correlating these measures with anthropometric maternal characteristics and perinatal outcomes.

Methods: An analytical prospective longitudinal study was conducted at a clinic in Rio de Janeiro, Brazil, between March 3, 2008, and March 30, 2012, among women with singleton pregnancies who had previously undergone RYGB. Participants received daily oral supplementation with 5000 IU retinol and 15 mg zinc. Variables assessed included vitamin A status (serum retinol and β-carotene; gestational night blindness), serum zinc concentration, maternal anthropometry, complications during pregnancy, and perinatal outcomes.

Results: Overall, 30 women participated. In all trimesters, more than 60% had inadequate serum levels of retinol or β-carotene. Night blindness was reported by 17 (57%) women in each trimester. Only 6 (20%) women had zinc inadequacy in the first and third trimesters. No significant association was observed between serum retinol or zinc and maternal anthropometry and birth weight. Vitamin A deficiency was associated with urinary tract infection (first trimester, P=0.020) and dumping syndrome (third trimester, P=0.013).

Conclusion: Despite RYGB and nutritional deficiencies (especially of vitamin A and zinc) increasing risks during pregnancy, there was no apparent fetal compromise when considering the analysis of birth weight and length of pregnancy at birth.

Keywords: Obesity; Perinatal outcomes; Pregnancy; Roux-en-Y gastric bypass; Vitamin A; Zinc.