What Are Flavonoids and Vitamin P?

Reviewed by Dan Brennan, MD on November 27, 2021

Flavonoids, sometimes called vitamin P, are found in lots of different fruits and vegetables. They might have benefits for your health.

Flavonoids and Vitamin P

Flavonoids are a large group of plant chemicals naturally found in many foods. They’re sometimes also called bioflavonoids or polyphenols.  

Flavonoids were discovered in 1930 when a new substance was separated from oranges. At the time, scientists thought it was a new class of vitamin and named it vitamin P. Later, it became clear that it wasn’t actually a vitamin.

There are about 6,000 different types of flavonoids. Plants use these compounds for their own growth. They help plants attract pollinators and fight infections. They give some fruits and vegetables their deep, rich colors.

Flavonoids aren’t considered essential nutrients. This means your body doesn’t need them to grow or develop. But eating flavonoid-rich foods can help lower your risk of chronic disease.

You can buy many flavonoid supplements. But, as with most nutrients, it’s probably best to get them in food. 

Types of Flavonoids

There are six main classes of flavonoids.

Flavonols. The most studied flavonols are quercetin, myricetin, and fisetin. Flavonols are linked to many different health benefits, including a lower risk of heart disease.  They’re found in:

  • Lettuce
  • Tomatoes
  • Onions
  • Kale 
  • Apples
  • Grapes
  • Berries
  • Tea
  • Red wine

Isoflavones. These compounds are found mostly in legumes and soybeans and, less commonly, in other plants. Some are considered to be phytoestrogens – a form of estrogen that we can get from food.

Flavanones. All citrus fruits like oranges, lemons, and grapefruits, have flavanones. These compounds make citrus juice and peels taste bitter. These compounds help to:

  • Lower inflammation
  • Act as antioxidants
  • Lower cholesterol
  • Lower fat levels in your blood

Flavanols. Flavanols are also called flavan-3-ols or catechins. Black tea, oolong tea, and chocolate are rich in catechins. They’re also found in fruit, including:

  • Bananas
  • Blueberries
  • Peaches
  • Apples
  • Pears 

Anthocyanins. The color of red, purple, and blue fruits comes from anthocyanins. Anthocyanins are found in:

  • Red grapes
  • Cranberries
  • Raspberries
  • Strawberries
  • Blueberries
  • Bilberries
  • Blackberries

Chalcones. These are thought to have antioxidant properties. Some types of these compounds are used in beauty products. Foods high in chalcones include:

  • Tomatoes
  • Pears
  • Strawberries
  • Bearberries
  • Wheat 

Health Benefits of Flavonoids

Experts are still studying how flavonoids affect health. We need more research, but some of the potential benefits include:

Antioxidant effects. Your body makes free radicals, unstable molecules that can damage cells.  This damage can lead to inflammation and contribute to other problems like cancer and heart disease. 

Antioxidants help to neutralize free radicals. Flavonoids have been shown to have antioxidant effects. They might be helpful in preventing chronic disease, but your body may not absorb them as well as other antioxidants like vitamin C. 

Heart disease prevention. Flavonoids might lower your risk for heart disease. Their antioxidant activity could help lower inflammation and blood pressure

Diabetes prevention. Flavonoids may reduce your risk for type 2 diabetes. They improve how your body uses glucose and digests carbohydrates. A study of 200,000 men and women showed that those who ate lots of flavonoids had a lower risk of diabetes. 

Brain health. Flavonoids might protect your brain by lowering inflammation and protecting your vascular system. Studies show a type of flavonoids found in cocoa could improve brain function, memory, and blood flow to the brain. 

Considerations for Flavonoids

The research on flavonoids is promising, but it’s still early. It’s clear that food plays an important role in your heart health and overall risk for disease. While flavonoids aren’t essential for health like vitamins are, they’re found in many fruits and vegetables that are good for your body.

Among flavonoid supplements, quercetin is a popular choice. But we need more research to understand how these supplements might affect your medications and organs such as your thyroid.

Since flavonoids are mostly known for antioxidant activity, it’s probably better to eat foods that naturally have several different antioxidants than to take supplements. A cup of strawberries, high in both vitamin C and flavonoids, might do more for you than a vitamin C pill or a flavonoid supplement.

If you want to benefit from the potential of flavonoids, add more fruits and vegetables to your diet. 

Show Sources


Advances in Nutrition: “Flavonoids.”

Biomolecules: “Flavonoids and Their Anti-Diabetic Effects: Cellular Mechanisms and Effects to Improve Blood Sugar Levels.”

Harvard T.H. Chan School of Public Health: “Antioxidants.”

Journal of Enzyme Inhibition and Medicinal Chemistry: “A comprehensive review on tyrosinase inhibitors.”

Journal of Nutritional Science: “Flavonoids: an overview.”

Oregon State University: “Flavonoids.”

Roczniki Panstwowego Zakladu Higieny: “Flavonoids – Food Sources and Health Benefits.”

Scientific World Journal: “Chemistry and Biological Activities of Flavonoids: An Overview.”

© 2021 WebMD, LLC. All rights reserved. View privacy policy and trust info