Is Vitamin C (Ascorbic Acid) Safe with Furosemide?
Free · No account · based on published sources including NIH ODS, FDA drug labels, and peer-reviewed literature
Consider ensuring adequate dietary vitamin C intake (75–90 mg/day minimum) or a modest supplement of 250–500 mg daily. This is especially relevant in elderly patients or those with heart failure on long-term furosemide therapy.
Why this interaction occurs
Loop diuretic-induced oxidative stress and increased urinary excretion of water-soluble vitamins including ascorbic acid have been documented. Studies in heart failure patients on furosemide show reduced plasma vitamin C levels, which may worsen endothelial dysfunction and oxidative damage. Vitamin C also plays a role in vascular protection relevant to cardiovascular patients.
Evidence
Evidence level: moderate.
Reported safety data
The FDA’s adverse event reporting system (FAERS) has received 274,011 reports mentioning Furosemide. This reflects reported cases involving the medication in general — not confirmed causation, and not specific to the Furosemide + supplement combination on this page.
FAERS reports are voluntary and cannot prove that a drug caused an event. Do not use report counts to assess the safety of this specific drug-supplement pair.
Frequently asked questions
Related interactions
All Vitamin C (Ascorbic Acid) interactions → · All Furosemide interactions →
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Educational only — not medical advice.
Always confirm with your doctor or pharmacist.