Flavonoids are phytonutrients present in fruits and vegetables. Lemon bioflavonoid, extracted from citrus peels, is a common supplement form.
People take them for heart health and immune function. These compounds work alongside vitamin C in the body, but they do not boost its absorption.
Take citrus bioflavonoids with food, often together with vitamin C. Doses differ across forms and products.
Flavonoids can mildly thin the blood. Speak with a doctor before using them if you take blood thinners or antiplatelet drugs. Their safety in pregnancy and breastfeeding is unknown.