Co-twin control studies: vitamin C and the common cold.
D001205:Ascorbic Acid / Q000627:therapeutic use*; D003139:Common Cold / Q000517:prevention & control*; D004200:Diseases in Twins; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D010641:Phenotype; D010919:Placebos; D011247:Pregnancy; D014427:Twins; D014430:Twins, Monozygotic
D010919:Placebos; D001205:Ascorbic Acid