Large Amounts of Vitamin C Increase Risk of Kidney Stones

Men who consume high levels of vitamin C are at twice the risk of kidney stones than men who do not.

In the current study, published in JAMA Internal Medicine, the investigators followed over 23,000 Swedish men who were between 45 and 79 years old in 1997 up to the year 2009. None of them had kidney stones at baseline.

Close to 900 of the men took 1,000-milligram doses of vitamin C, and 3 percent of them (31 men) later had kidney stones. Less than 2 percent of those in the rest of the group developed kidney stones.

The researchers adjusted for factors which could undermine the reliability of the findings, such as education levels, ages, and body weights.

They revealed that those men who received the high-dose supplements had an elevated kidney stone risk ranging between 1.7 and 2.2 times.

The authors point out that there are no significantly proven reasons for any person to take such large amounts of vitamin C. The results of the study do not apply to vitamin C that comes from food.

Another outcome of the study was that multivitamin supplements that don't have large doses of vitamin C did not increase the risk of kidney stones.

The authors point out that more studies are needed to back up these findings, and they emphasize that people should not stop consuming vitamin C after reading this report. If you are concerned about your vitamin C intake or any health consequences related to vitamin supplementation, talk to your doctor.

Last year, a study presented at the Endocrine Society's 94th Annual Meeting in Houston, revealed that vitamin C and vitamin D supplements are associated with high calcium levels in the urine and blood,. High urine/blood calcium levels are linked to a higher risk of kidney stones.