Study Shows Taking Vitamin C Daily Doubles Risk Of Kidney Stones, Especially For Men

Research reported in Monday’s JAMA Internal Medicine indicates men who supplement their vitamin C daily are at a higher risk of developing kidney stones. Kidney stones are hardened, calcified masses that accumulate in the kidneys from oscillating one’s diet, taking certain medications such as diuretics, heredity, dehydration, chronic inflammatory diseases, metabolic disorders, and pregnancy. They can crystalize in one or both kidneys and when not asymptomatic, are excruciatingly painful when passed, according to the US Department of Health and Human Services.

Swedish researchers, noticing the sudden rise in kidney stones, surmise copious doses of vitamin C is the culprit.

Laura Thomas, from the Karolinska Institutet (Institute) in Stockholm, proposes:

“It has long been suspected that high doses of vitamin C may increase the risk of kidney stones.”

Vitamin C is an essential nutrient and antioxidant for the human body. It’s responsible for several enzymatic reactions necessary for wound-healing, like collagen synthesis. It is also essential for bone and muscle health. Vitamin C staves off conditions such as scurvy. Initial onset of scurvy causes bleeding of the gums and lethargy. Over time, as the condition progresses, fever, suppurating (puss) wounds, jaundice, and death can result.

Vitamin C is water soluble, which means unlike fat soluble nutrients, it is not stored for prolonged periods in the body. Once the body has absorbed the necessary or desired amount, the remainder is excreted in urine as oxalate. Hence why many nutritionists suggest supplementing with vitamins to be a waste of money. This oxalate is a component found in kidney stones. Calcium oxalates are also associated with kidney stones.

The study analyzed 907 men who took regular vitamin C versus more than 22,000 individuals who did not. The average supplement taken contained 1,000 mg of vitamin C. An 8 ounce glass of orange juice typically contains 120 mg. Of the supplement users (907) 3.4 percent were afflicted with kidney stones versus 1.8 percent of non-supplement takers (22,000).

Therefore, excessive amounts of vitamin C, similar to that of calcium, when unused by the body is filtered through the kidneys as waste. Over time, as a pearl accumulates in an oyster, so does oxalates crystalizing and forming kidney stones. People whom have had kidney stones in the past are predisposed to develop them again and may want to reconsider excessive dietary supplementation with vitamin C and calcium.

This study is not indented to discourage ingesting foods with high concentrations of vitamin C, as again it is necessary for human development and maintaining proper metabolic and recuperative functions. It is simply a caution to not overdose.

The US 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. Amounts greater than 2,000 mg per day are not recommended because such high doses can lead to stomach upset and diarrhea.

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