A prospective study of the intake of vitamins C and B6, and the risk of kidney stones in men.
OBJECTIVE
The association between the intake of vitamins C and B6, and kidney stone formation was examined.


METHODS
We conducted a prospective study of the relationship between the intake of vitamins C and B6 and the risk of symptomatic kidney stones in a cohort of 45,251 men 40 to 75 years old with no history of kidney calculi. Vitamin intake from foods and supplements was assessed using a semiquantitative food frequency questionnaire completed in 1986.


RESULTS
During 6 years of followup 751 incident cases of kidney stones were documented. Neither vitamin C nor vitamin B6 intake was significantly associated with the risk of stone formation. For vitamin C the age-adjusted relative risk for men consuming 1,500 mg. daily or more compared to less than 250 mg. daily was 0.78 (95% confidence interval 0.54 to 1.11). For vitamin B6 the age-adjusted relative risk for men consuming 40 mg. daily or more compared to less than 3 mg. daily was 0.91 (95% confidence interval 0.64 to 1.31). After adjusting for other potential stone risk factors the relative risks did not change significantly.


CONCLUSIONS
These data do not support an association between a high daily intake of vitamin C or vitamin B6 and the risk of stone formation, even when consumed in large doses.
Curhan
G C
GC
Department of Epidemiology, Harvard School of Public Health, Boston, Massachusetts 02115, USA.
Willett
W C
WC
Rimm
E B
EB
Stampfer
M J
MJ
D001205:Ascorbic Acid / Q000008:administration & dosage* / Q000009:adverse effects; D015331:Cohort Studies; D004032:Diet; D002149:Energy Intake; D006282:Health Personnel; D006801:Humans; D015994:Incidence; D007669:Kidney Calculi / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011736:Pyridoxine / Q000008:administration & dosage* / Q000009:adverse effects; D012307:Risk Factors; D013997:Time Factors; D014481:United States / Q000453:epidemiology
D011736:Pyridoxine; D001205:Ascorbic Acid