If you have nutritional gaps in your diet or are simply making an effort to improve your health, you may reach for supplements to give your body a boost. However, it’s crucial to keep the potential risks in mind. Even common vitamins that seem harmless can have negative effects when consumed in excess. Monitoring your dosage and being mindful of what you’re putting into your body—even if you find it at the supplement aisle—is an integral part of keeping your health and safety in check. High doses of certain supplements can pose a risk to your liver, your heart, and your kidneys. In fact, some could contribute to kidney stones.
To shed light on two vitamins that might lead to kidney stones in excessive doses, we spoke to Dr. Olalekan Otulana, GP and physician at Cassioburt Court. He told us that vitamin C and vitamin D are two to tread lightly with. Find all of his expert insight on how these vitamins could be detrimental to your kidneys below.
Struggling With Sleep? This Rechargeable Sound Machine Is A Total Game-Changer
Vitamin C
Vitamin C is an undeniably essential vitamin. It's well-known for its immune-supporting benefits. However, too much of it could lead to kidney stones. "High doses of vitamin C, especially in supplement form, can lead to an increased excretion of oxalate in the urine, which is one of the key substances that form kidney stones," says Dr. Otulana.
Does that mean you should cut back on oranges? There's no need to worry about that. This concern applies mostly to vitamin C supplements—not the vitamin C you get naturally from food like citrus fruits, berries, or vegetables. It’s the large, daily supplemental doses that can contribute to elevated oxalate levels, which may combine with calcium in the urine to form stones. If you’re already prone to kidney stones or have a family history, this is especially worth paying attention to.
Vitamin D
Vitamin D, also essential, plays a vital role in supporting bone health and calcium absorption. But like Vitamin C, it may contribute to kidney stones in certain situations. According to Dr. Otulana, "If someone is taking high doses of vitamin D along with calcium supplements, it can raise calcium levels in the urine, which may also contribute to stone formation in susceptible individuals."
This doesn’t mean you should avoid vitamin D altogether, even in supplement form. In fact, especially in the winter months, vitamin D supplementation can be critical at times of limited sun exposure. However, over-supplementing, particularly in combination with calcium, can backfire if not managed properly.
How to Stay Safe with Supplements
All in all, it's always best to proceed with caution when it comes to supplements. There are a few precautions you can take to reduce impact on your kidneys. For starters, Dr. Otulana says, if you’re taking any supplements regularly—especially in high doses—hydration is key. Staying well-hydrated helps flush your kidneys and reduces the concentration of stone-forming substances in your urine.
Ultimately, the best way to go is to aim to get most of your essential vitamins from a balanced diet, follow recommended daily values, and speak to a healthcare provider before starting or continuing any high-dose vitamin regimen. Because while supplements can be beneficial when used correctly, they’re not always harmless.
