Vitamin C and Kidneys: Stones, Disease, and More


The kidneys filter excess vitamin C from your body. Vitamin C intake may lower your risk for kidney cancer. However, high doses may increase your risk of developing kidney stones.

Vitamin C is an important nutrient for the body. It helps you absorb iron from foods and heal from cuts and bruises. It also plays a role in repairing bones and tissues in your body.

The National Institutes of Health (NIH) recommends a dietary allowance of 90 milligrams (mg) per day for adult males and 75 mg per day for adult females.

However, if your kidneys aren’t functioning properly or you regularly consume high levels of vitamin C, you may increase your risk of developing certain health complications.

Keep reading to learn more about the connection between vitamin C and kidney health.

A 2023 review suggests that vitamin C may have anti-inflammatory and anti-oxidative benefits for people living with chronic kidney disease (CKD).

Vitamin C supplementation may also be recommended if you’re undergoing dialysis. This type of treatment helps filter your blood with a machine. A 2021 review noted one study in which dialysis lowered participants’ mean vitamin C levels by 67%.

However, high levels of vitamin C may also have harmful effects if you have CKD.

For example, when you consume between 30–180 mg of vitamin C per day, your body typically absorbs 70–90% of it. Then, your kidneys excrete the excess through urine.

Vitamin C can be transformed into oxalate in your body, which your kidneys also filter.

However, if you have CKD, your kidneys can’t filter as much waste products from your body. This may cause a buildup of oxalate in your body, which has been associated with several health conditions, including:

  • kidney failure
  • kidney stones
  • inflammation

It’s important to speak with a healthcare professional about vitamin C supplementation, especially if you have CKD.

Kidney stones happen when waste accumulates and clumps together in your kidneys, causing pain and difficulty urinating.

According to the National Kidney Foundation, more than half a million people seek emergency care for kidney stones every year, and 1 in 10 people will get kidney stones in their lifetime.

High doses of vitamin C can increase your risk of the most common type of kidney stone, calcium oxalate. This is because high doses of vitamin C are partly metabolized into oxalate, which can then clump into crystals.

The vitamin C you get from food isn’t likely to be high enough to lead to kidney stones. However, vitamin C supplements (such as ascorbic acid tablets) could increase the risk.

A 2019 meta-analysis found that males were more likely to get kidney stones from vitamin C supplementation than females. The authors note that 250–499 mg per day and 1000–1499 mg per day were the doses that posed the highest risk. Surprisingly, doses of 500–1000 mg and greater than 1500 mg per day did not correlate, but it’s unclear why.

To help minimize the risk of kidney stones, the NIH recommends that adults consume no more than 2,000 mg per day.

Research suggests that vitamin C intake may play a role in lowering your risk of renal cell carcinoma. For example:

  • A 2022 review suggested that an increased intake of vegetables and vitamin C was associated with a lower risk of kidney cancer.
  • A 2015 meta-analysis found that people with a higher vitamin C intake had a lower risk of kidney cancer.
  • A 2019 study found that vitamin C intake alongside chemotherapy may help increase the effects of chemotherapy without increasing its side effects.

Researchers have been exploring the potential of using high doses of vitamin C to treat cancer for decades. But it’s important to note that vitamin C has not been approved by the Food and Drug Administration for cancer treatment.

The National Cancer Institute (NCI) suggests that high levels of vitamin C are not recommended for people with kidney cancer because it could do more damage.

Our bodies can’t make vitamin C. Instead, we get it from food or supplements.

Vitamin C offers several important benefits for the body, including:

  • helping wounds heal
  • protecting cells from damage
  • keeping blood vessels, skin, bones, and cartilage healthy
  • improving absorption of other nutrients

Vitamin C deficiency can lead to scurvy, a condition that can cause serious complications throughout the body.

It can be hard to assess your vitamin C levels because the nutrient is found all over the body. Researchers will often use the blood concentration of vitamin C to figure out how much of the vitamin is in your body.

Your levels of vitamin C may also change quickly if you take a supplement or the vitamin is given intravenously.

Many fruits and vegetables are rich in vitamin C, including:

  • red and green bell peppers
  • strawberries
  • kiwis
  • oranges
  • grapefruit
  • potatoes
  • tomatoes
  • broccoli
  • cantaloupe
  • cabbage
  • cauliflower

Most adults need between 75 and 90 mg of vitamin C per day. However, you may need an extra 35 mg of vitamin C if you smoke. Smoking increases oxidative stress, which reduces your vitamin C levels.

If you think you’re not getting enough vitamin C in your diet, speak with a healthcare professional. They’ll help you find a solution, which may involve taking a vitamin C supplement.

It’s important to remember that vitamin C supplementation may increase your risk of kidney stones if you have CKD.

Is vitamin C good for the kidneys?

Vitamin C may have anti-inflammatory and anti-oxidative benefits if you have CKD. Some animal studies suggest that vitamin C may also help protect your kidneys from injury and speed up the healing process.

That said, high levels of vitamin C can increase your chances of developing kidney stones.

Does vitamin C increase creatinine?

Vitamin C may help decrease the levels of creatinine in your body. For example, a 2021 review found that vitamin C helped increase creatinine clearance in people who underwent kidney transplant surgery.

Is 1,000 mg of vitamin C too much?

The NIH recommends that adults don’t consume more than 2,000 mg per day. However, this amount may differ for people living with CKD.

Vitamin C is an important nutrient found in many fruits and vegetables. It helps the body heal wounds and protects cells from damage.

Vitamin C may also affect kidney health. Higher levels have been associated with lower rates of kidney cancer. However, high doses of vitamin C supplements may increase your risk of kidney stones.

Speak with a healthcare professional if you’re considering adding a vitamin C supplement to your diet.


Leave a Reply

Your email address will not be published. Required fields are marked *