If you are one of those who regularly consume vitamin C supplements, you may need to be more cautious now. A research from Sweden shows that men who take vitamin C supplements are at higher risk of developing kidney stones.
Researchers led by Laura Thomas of the Karolinska Institutet in Stockholm used data from a large study of middle-aged and elderly Swedish men who answered a series of questions on their diet and lifestyle, then were tracked for an average of 11 years.
The current analysis included 907 of those men who said they took regular vitamin C tablets and more than 22,000 who didn’t use any nutritional supplements.
Of the vitamin C users, 3.4 percent developed kidney stones for the first time during the study, compared to 1.8 percent of non-supplement users. Men who took vitamin C supplements – which typically contain 1,000 mg per tablet – at least once a day had the highest risk of kidney stones, researchers reported in JAMA Internal Medicine.
“It has long been suspected that high doses of vitamin C may increase the risk of kidney stones as some of the vitamin C absorbed by the body is excreted in urine as oxalate – one of the key components of kidney stones,” Thomas said
Stones are made up of tiny crystals, which can be formed by calcium combining with oxalate. They usually pass on their own, but can cause severe pain in the process. Larger stones occasionally require surgery. Men are more likely to form stones than women.
This doesn’t mean that people should stop consuming vitamin C. Vitamin C is an important part of a healthy diet and you can get it naturally from fruits and vegetables. Its negative effect on kidney stone risk is likely to depend both on the dose and on the combination of nutrients with which it is ingested.
Swedish supplements, like those the study participants would have taken, typically contain about 1,000 milligrams (mg) of vitamin C per tablet. Most vitamin C supplements sold in the U.S. contain either 500 or 1,000 mg. The U.S. Institute of Medicine recommends 90 mg per day for men – the amount in a small glass of orange juice or a cup of broccoli – and 75 mg for most women.
However, short term use of higher dose vitamin C can be helpful when people have a cold and may not constitute a risk for kidney stones.
(Source: reuters)
Leave a Reply