January 2021

Kidney Stone Scare? Skip these Supplements

Kidney stones can be extremely painful. Once a patient experiences one stone, the chances of another stone forming go up significantly. It’s important for patients to understand that some diets and natural medicines can increase the risk for stones.

There are a number of ingredients to watch out for. One big culprit is vitamin C. This is particularly relevant as many patients consider the use of high-dose vitamin C to boost immune function during the COVID-19 pandemic. Taking 1 gram of vitamin C daily – the amount found in many immune supplements such as Immune+ Plus by Emergen-C – can increase the risk of kidney stones by 40% in people with a history of stones. And in some men, taking a supplement containing as little as 250 mg vitamin C daily might increase stone risk. Tell patients who are prone to kidney stones to avoid taking large doses of vitamin C. Rather than taking supplements, advise patients to focus on incorporating adequate vitamin C into their diet – eating just one cup of strawberries and one orange daily should provide 200 mg.

Like vitamin C, high doses of vitamin D are being promoted for COVID-19. Taking these high doses long-term can increase calcium levels in some people, which can lead to kidney stones. Reiterate that very high doses aren’t necessary, and that 400-1000 IU daily should result in adequate vitamin D levels for most people.

Cranberry and soy are other ingredients to watch out for – both contain high amounts of oxalates. Tell patients to avoid cranberry extract products and large amounts of cranberry juice if they’re at risk for kidney stones. And while soy milk and soy sauce aren’t concerning, tell patients to avoid high amounts of soy foods with less processing, like edamame, soy flour and tempeh. The oxalate content in tofu can vary, but it generally contains lower amounts.

In addition to supplements and natural ingredients, people at risk for kidney stones should avoid certain diets – particularly those focused on inducing ketosis, like the ketogenic diet and modified Atkins diet. Talk to patients about their dietary habits, particularly as New Year’s resolutions kick off and new weight loss plans commence. Steer patients at risk for kidney stones towards other options, like the Mediterranean diet.

The information in this brief report is intended for informational purposes only, and is meant to help users better understand health concerns. This information should not be interpreted as specific medical advice. Users should consult with a qualified healthcare provider for specific questions regarding therapies, diagnosis and/or health conditions, prior to making therapeutic decisions. Copyright © 2024 NatMed. Commercial distribution or reproduction prohibited. NatMed is the leading provider of high-quality, evidence-based, clinically-relevant information on natural medicine, dietary supplements, herbs, vitamins, minerals, functional foods, diets, complementary practices, CAM modalities, exercises and medical conditions. Monograph sections include interactions with herbs, drugs, foods and labs, contraindications, depletions, dosing, toxicology, adverse effects, pregnancy and lactation data, synonyms, safety and effectiveness.