Genetic variation at the SLC23A1 locus is associated with circulating concentrations of L-ascorbic acid (vitamin C): evidence from 5 independent studies with >15,000 participants. - Timpson NJ; Forouhi NG; Brion MJ; Harbord RM; Cook DG; Johnson P; McConnachie A; Morris RW; Rodriguez S; Luan J; Ebrahim S; Padmanabhan S; et al. (American Journal of Clinical Nutrition, 2010)