The Difference Between Phytonutrients and Vitamins


Most grew up being told that their diet should contain plenty of vitamins. That advice is still sound today. However, it’s a sure bet that most people were never told to eat their phytonutrients. This article will explain the difference between these two commonly-confused compounds and detail the importance of each.

Let’s start with vitamins. There are 13 vitamins that are required for normal growth and development. These vitamins must also be consumed in adequate amounts to support normal body functions throughout the lifespan. The Food and Drug Administration determines the recommended daily amount of vitamins that should be eaten each day. Vitamins and the areas of health that they support are:

• Vitamin A: vision, skin, hair, bones, immunity
• Vitamin C: antioxidant
• Vitamin D: bones, teeth
• Vitamin E: antioxidant
• Vitamin K: blood clotting
• B vitamins including B-6, B-12, folate, thiamine, riboflavin, niacin, pantothenic acid, and biotin: energy production, red blood formation, nervous system

A deficiency in any one of these vitamins can result in poor health. For example, if 12 of the 13 vitamins are eaten in adequate amounts, but Vitamin A intake is low, night blindness and lowered immunity may be the result.

There is another class of nutrients that also supports health phytonutrients. There are literally thousands of phytonutrients. Interestingly enough, some of the phytonutrients are also vitamins specifically, vitamins A, C, E, K and folate.

Phytonutrients differ from vitamins in that phytonutrients are found only in plant-based foods fruits, vegetables, seeds, nuts, legumes, grains and tea.

Phytonutrients contain disease-preventing compounds that strengthen immunity and offer anti-aging benefits. The specific effects of phytonutrients in the body vary tremendously, ranging from antioxidants to hormone metabolism to anti-carcinogen activity. Phytonutrients are categorized based on their structure or their function. The major classes of phytonutrients classes are:


The indoles are found in foods that contain high vitamin C levels. Indoles work in synergy with vitamin C to offer many health benefits including anti-carcinogenic effects, inhibition of free radical activity, aiding in hormonal balance, and enhancing cell nourishment.


Examples of phenols include resveratrol and isoflavones. Phenols serve to prevent oxidative damage from free radicals. They also have a strong protective role in the cardiovascular system including lowering blood pressure, clot formation, and vascular inflammation. The isoflavones have been shown to reduce the risk for osteoporosis, cancer, and heart disease.


Phytosterols are found in green and yellow vegetables and aloe vera juice. Their primary function is to block cholesterol absorption and to rid the body of extra cholesterol, both of which may help reduce risk of cardiovascular disease. Phytosterols are also strong anti-carcinogens, especially helpful in the prevention of prostate, colon, and breast cancer.


Terpenes are found in green fruits and vegetables as well as in soy products and grains. Terpenes are strong antioxidants that protect against free radical proliferation and tumor growth. Beta-carotene is a terpene that reduces the risk of macular degeneration and various cancers including lung, colorectal, breast, uterine and prostate


Thiols are found in onions, garlic, and cruciferous vegetables. The thiols also prevent cancer and cardiovascular disease. Thiols can also inhibit the activity of toxins produced by certain bacteria.

To answer the original question. What is the difference between phytonutrients and vitamins? Vitamins are compounds that are contained in a variety of foods and help to maintain normal functions in the body. Phytonutrients are found exclusively in plants and improve human health. Unfortunately, only half of Americans eat enough vegetables each day and one-third eat enough fruit.

It’s important to consume vitamins and phytonutrients in whole foods not from a synthetic supplement. It’s easy to become hyperfocused on the health benefits of a certain vitamin or phytonutrient, but in isolation, these compounds offer limited benefit. Vitamins and phytonutrients are most effective when consumed in whole foods. Also, whole foods contain additional cofactors and enzymes, which act synergistically to enhance absorption of these compounds in the body.

The concept of food synergy is now a well-accepted term in the scientific community. Food synergy is the synergistic influence of foods and the components found in foods on human health. Most experts now recommend a “top down” approach, which is to eat a diet that emphasizes a wide variety of whole foods with an emphasis on fruits and vegetables.

Dr. Linda Kennedy MS SLP ND


Jacobs DR Jr, Gross MD, Tapsell LC. Food synergy: an operational concept for understanding nutrition. Am J Clin Nutr. 2009 Mar 11. [Epub ahead of print]

Jacobs DR Jr, Steffen LM. Nutrients, foods, and dietary patterns as exposures in research: a framework for food synergy. Am J Clin Nutr. 2003 Sep;78(3 Suppl):508S-513S. Review.

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