Wizard of Vitamins

Quercetin Vitamin

What is Quercetin?

Quercetin belongs to a class of water-soluble plant pigments called flavonoids.

Quercetin in Diets

Quercetin can be found in onions, apples, green tea, and black tea. Smaller amounts are found in leafy green vegetables and beans.

Quercetin Medicinal Treatments

Prostatitis (nonbacterial prostatitis, prostadynia) Allergies Asthma Atherosclerosis Capillary fragility Cataracts Childhood diseases Edema (water retention) Gout Hay fever Peptic ulcer Retinopathy Type 1 diabetes Type 2 diabetes

Known Consequences of Quercetin Deficiency

No clear deficiency of quercetin has been established.

Quercetin Recommended Dosages

Some doctors recommend 200–500 mg of quercetin taken two to three times per day. Optimal intake remains unknown.

Quercetin Side Effects

No clear toxicity has been identified. Early quercetin research suggested that large amounts of quercetin could cause cancer in animals. Most, but not all, current research finds quercetin to be safe or actually linked to protection from cancer. Quercetin has been shown to cause chromosomal mutations in certain bacteria in test tube studies. Although the significance of this finding for humans is not clear, some doctors are concerned about the possibility that birth defects could occur in the offspring of people supplementing with quercetin at the time of conception or during pregnancy. Since flavonoids help protect and enhance vitamin C, quercetin is often taken with vitamin C. Certain medicines may interact with quercetin. Refer to drug interactions for a list of those medicines.