The Age of Information is also the Age of Misinformation — Claims Regarding Vegetarianism and Vitamin A

by Ricardo Racicot

In today's age of information we are able to access the answer to almost any question within seconds. With access to the Internet and search engines at our fingertips, thanks to smartphones and laptops, any inquiry or dispute can be settled immediately. Unfortunately, this is a double-edged sword. While we may have swift access to information, there is no assurance that it is accurate. This is especially true regarding nutrition information. There are countless resources on the Internet claiming to be legitimate sources, many of which have an agenda. These sources include advocacy groups promoting a particular agenda and may posit legitimate sounding ideas as science when the background information is not there. This, I believe, perpetuates myths and poor-quality information, directly resulting in stigmatizing vegetarians and misinformation about their diets.

A few months ago, I saw a Facebook posting from one such advocacy group claiming, "Carrots are not a source of vitamin A. Vitamin A is found exclusively in animal foods." While I am not a vegetarian, this type of misinformation concerns me because it may dissuade people from pursuing a healthy vegetarian lifestyle. Claims such as this are unfounded and based on a poor understanding of science, and I would like to dispel some common myths surrounding vegetarianism and vitamin A.

Claim: Vitamin A is found exclusively in animal foods

Technically, this is correct. However, it's highly misleading. Vitamin A in its complete form, retinol, is only found in animal products; however, the precursors to vitamin A are found in a plethora of fruits and vegetables, including carrots, mango, spinach, and sweet potatoes. When we eat foods containing these precursors, such as beta-carotene, our body converts them to vitamin A. The rate of conversion from beta-carotene to retinol varies widely depending on a number of factors and ranges from a 3.8:1 to 28:1 ratio, meaning it requires somewhere between 3.8 to 28 units of retinol precursors to make a single unit of retinol.1 Because of the variation in the conversion rate of carotenoids to retinol, daily vitamin A requirements are expressed in micrograms (mcg) of Retinol Activity Equivalents (RAE), a unit that takes into consideration the ease of absorption depending on the source of vitamin A. Many plant-based sources actually have a higher RAE than their animal-based counterparts, with the major exception being beef liver. While plant-based foods are not a source of complete vitamin A, they provide our bodies with the necessary building blocks to meet our vitamin A requirements.

Dish Cooking Method mcg RAE/Cup
Beef Liver Pan Fried 9,680
Sweet Potato Boiled 2,581
Carrot Boiled 1,329
Spinach Boiled 943
Eggs Boiled 203
Coho Salmon Dry Heat 80
Chicken Breast (skinless) Roasted 8

The daily Recommended Dietary Allowance of vitamin A for adult males is 900 mcg RAE and 700 mcg for females.

Source: U.S. Department of Agriculture, Agricultural Research Service. 2013. USDA National Nutrient Database for Standard Reference, Release 26. Nutrient Data Laboratory Home Page,