However, the magnitude of the benefit has substantially varied, hampering conclusions about the clinical significance of the vitamin. It was found that on average, vitamin C produces greater benefit for children than for adults. The trials analyzed in this work used regular vitamin C supplementation, but it is conceivable that therapeutic supplementation starting early at the onset of the cold episode could produce comparable benefits. Since few trials have examined the effects of therapeutic supplementation and their results have been variable, further therapeutic trials are required to examine the role of vitamin C in the treatment of colds. Intake of vitamins B6 and C and the risk of kidney stones in women.
Urinary oxalate is an important determinant of calcium oxalate kidney stone formation.
High doses of vitamin B6 may decrease oxalate production, whereas vitamin C can be metabolized to oxalate. This study was conducted to examine the association between the intakes of vitamins B6 and C and risk of kidney stone formation in women. The relation between the intake of vitamins B6 and C and the risk of symptomatic kidney stones were prospectively studied in a cohort of 85,557 women with no history of kidney stones. Semiquantitative food-frequency questionnaires were used to assess vitamin consumption from both foods and supplements. A high intake of vitamin B6 was inversely associated with risk of stone formation.