“…However, it is still unknown whether it is optimal to maintain plasma PLP concentrations >20 nmol/L during pregnancy (Simpson et al, 2010). Few clinical studies have suggested that high vitamin B 6 status during pregnancy is associated with decreased prenatal nausea and vomiting (Babaei & Foghaha, 2014;Sahakian, Rouse, Sipes, Rose, & Niebyl, 1991;Vutyavanich, Wongtra-ngan, & Ruangsri, 1995), higher Apgar scores (Schuster et al, 1984;Temesvari et al, 1983), higher birth weights (Chang, 1999), reduced incidence of preeclampsia (de la Calle et al, 2003) and preterm birth (Ronnenberg et al, 2002), and a protection against orofacial clefts (Krapels et al, 2004) and cardiovascular malformations (Czeizel, Puho, Banhidy, & Acs, 2004;Salam et al, 2015). However, these purported associations have not unequivocally been demonstrated (Chen et al, 2015;Heller et al, 1973;Salam et al, 2015).…”