title: Vitamin A and seasonal variation.
mesh_terms: D002338:Carotenoids / Q000097:blood*; D000013:Congenital Abnormalities / Q000209:etiology*; D005260:Female; D006801:Humans; D008131:London; D011247:Pregnancy; D011248:Pregnancy Complications / Q000097:blood; D012621:Seasons; D014801:Vitamin A / Q000097:blood*; D014802:Vitamin A Deficiency / Q000097:blood / Q000150:complications
chemical_list: D014801:Vitamin A; D002338:Carotenoids