Small amounts of vinegar (especially apple cider vinegar) are generally safe for most people with IgAN who have stable kidney function. However, it should be used in moderation as part of a balanced diet. If you're taking medications or have decreased kidney function, check with your doctor first. Vinegar's acidity could potentially interact with certain medications.

Remember: Always dilute vinegar and never consume it straight, as this could irritate your digestive system. Start with small amounts (1-2 teaspoons in water) to see how your body responds.