A few weeks ago, we read an interesting article on kidney stones and vitamin C by a colleague from Men’s Health USA, and decided to share it online. To our surprise, the topic generated a rather heated debate, especially on the “correct” dosage of vitamin C. To get a clearer picture, we spoke to three experts, covering the spectrum of purpose, dosage and effect of vitamin C.
How Much Vitamin C Should You Consume?
The first tell-tale sign of overconsumption is diarrhoea, according to Kong Woan Fei, dietitian from the Columbia Asia Group. Although the tolerable upper intake level for vitamin C is said to be 2,000mg Recommended Nutrients Intake, she says adults should not ingest more than 1,000mg to avoid health risks.
Like Kong, Yeoh Ee Ling, education manager of Fitness Innovations, says that 1,000mg of vitamin C supplementation is agreeable to the body.
Bottom line: Consumption of 1,000mg of vitamin C supplementation is safe.
How About Vitamin C from Food?
Although the experts differ on the exact amount, it falls in the range of 70mg to 100mg. “Recommended dietary allowance is 90mg for males and 75mg for females,” Yeoh says. However, Kong says 70mg of vitamin C is sufficient for adults up to age 90. As for Datuk Dr. Selvalingam Sothilingam, consultant urologist from Columbia Asia Hospital - Cheras, he suggests adults consume between 90g and 100mg of vitamin C from food.
All three experts agree that vitamin C supplementation is unnecessary if you have a balanced diet. Dr. Sothilingam, for one, doesn’t believe in it. “The vitamin C that you get from food is enough for your body. You don’t need high doses to boost your immune system and antioxidant levels,” he says. To ensure you get enough, you just need to know which foods contain high levels of vitamin C, he adds. Citrus fruit, broccoli, sweet potatoes and cauliflower, for example, are rich in the micronutrient.
Bottom line: Vitamin C supplementation is not necessary if you have a balanced diet.
Who Really Needs Vitamin C?
Nevertheless, some are advised to boost their intake. “If you don’t eat healthfully, that’s when vitamin C supplementation can benefit you,” Dr. Sothilingam says.
Vitamin C can’t boost your athletic performance though, but it is essential if you have a high-intensity training regime, Yeoh says. Those in a weight-sensitive category or on a low-calorie diet might also need supplementation, as their vitamin C consumption from food would be lower.
Bottom line: Vitamin C supplementation is recommended for those who are not getting enough of the micronutrient from food.
Will I Get Kidney Stones?
No and yes. Consuming excessive amounts of vitamin C doesn’t always cause kidney stones, but it does increase their likelihood, Dr. Sothilingam says. However, “typically, stone formation is multifactorial,” meaning it is determined by a combination of factors such as your genes, urinary system and diet, he adds.
If you’re worried about stones in your kidneys, Dr. Sothilingam advises reducing your intake of sodium and purine, which are found in food such as red meat, nuts and offal. Bodybuilders should also be cautious when taking protein supplements, as they are known to increase the risk of kidney stones.
Bottom line: There is no definitive evidence that consuming excessive amounts of vitamin C will cause kidney stones. However, some studies have found that consuming more than 1,000mg of vitamin C over a period of time will increase the risk.
Due to the successful marketing of vitamin C supplements, some Malaysians think that they need to do more to ensure they take enough of the micronutrient – going so far as to get regular vitamin C shots from clinics, Dr. Sothilingam says. “They claim it gives them a feel-good factor, but a lot of that might be due to a placebo effect.”
Meanwhile, Yeoh wants to debunk a common belief. “Most people think that vitamin C ‘cures’ colds.” In truth, it only serves as a preventive measure, she explains.
Bottom line: Vitamin C is not a magic pill. It doesn’t treat colds; it can only make you less vulnerable to bugs.