Categories: FitnessGeneralHealthLongevityNutrition

What’s Up With Vitamin A?

What’s up with vitamin A and Cron-O-Meter? I have one lousy small carrot and I am at 278% of my daily requirement for vitamin A. Is that correct? And to add to it all, vitamin A is supposedly toxic at high doses. First, it is correct, and in this blog I will address what is going on and shed some light on what is up with vitamin A.

Carrots, spinach, kale, bell peppers, sweet potatoes, cantaloupe, apricots, broccoli, tomatoes, and asparagus are all excellent sources of vitamin A. Vitamin A will preserve and improve your eyesight and help you fight off viral infections. It is known as the “anti-viral vitamin”. It is also a fat-soluble vitamin and needs fat to dissolve it and transport it within the body. Deficiencies may be caused by a diet that is extremely low in fat.

There are two different types of vitamin A. The first type, preformed vitamin A (retinol), is found in meat, poultry, fish, and dairy products. The second type, provitamin A (carotenoids), is found in fruits, vegetables, and other plant-based products. The most common type of provitamin A in foods and dietary supplements is beta-carotene.   Preformed vitamin A and provitamin A is where the confusion comes in.

Toxicity can occur with excessive intakes of preformed vitamin A (retinol) and not necessarily with provitamin A (carotenoid) intake. The dosage levels that need to be obtained to cause toxicity are difficult to attain through food alone. Toxicity usually has been associated with prolonged supplement intake over a long period of time.

Symptoms of getting too much preformed vitamin A (retinol) can cause dizziness, nausea, headaches, coma, and even death according to the National Institute of Health (NIH).

Consuming high amounts of provitamin A can turn the skin yellow-orange in color, but this condition is harmless.

In Cron-O-Meter (CM) you can click on “vitamin A” and open a box that displays the daily recommended intakes (DRI), which are CM’s default settings. The range in the picture is for a fifty-year-old male.  These are also editable and you can put any range you desire into them.

The DRI’s and tolerable upper limits (UL) for preformed vitamin A can be found on the site www.nap.edu.   There are no limits established for provitamin A (carotenoids, beta-carotene).

We get a lot of questions when one carrot reflects 278% of your daily value, but we here at Cron-O-Meter can’t tell you what amount to take or what ranges to use. That decision is left to you and your healthcare team. We hope this blog will help you understand why CM states what it does and what it means allowing you to be better informed and make the decision that is best for your health.

Live well!

Frank Alvarez


Frank Alvarez :Frank Alvarez - Owner Frankly Nutritious. www.FranklyNutritious.com Frank turned his life around when he was racing as professional duathlete and adventure racer. He was "fit but not healthy", and pushed himself too far and became seriously ill. He found holistic nutrition and used it to turn his life around. You can can read his story at www.franklynutritious.com Frank graduated from the University of Wisconsin-Madison with a BS in Bacteriology. Shortly after his graduation he joined the Wisconsin Air National Guard (Air Force) where he flew KC 135s for 25 years. He has raced as a professional duathlete competing in five world championships. He is a Cory Holly Institute Certified Sports Nutrition Advisor, a Colgan Power lifting coach, a CHEK Holistic Life Coach, and is enrolled in a Masters of Holistic Nutrition course, which will lead into a PhD program. His passion in health and wellness and his military career fostered his Wellness For Me integrative program that partners with the individual to design a path to their optimum health vision. As owner of Wellness For Me, LLC, Frank is proud to bring you the programs Frankly Nutritious and Frankly Fit. Hawthorn University- Master of Science and Holistic Nutrition- 85% completed. 128 Air Refueling Wing Resiliency Instructor Certified Sports Nutrition Advisor- Cory Holly Institute Cooper Clinic Fitness Specialist CHEK Holistic Life Coach Colgan Institute- Level 1 Power Lifting Certified Coach Level-1 US Track & Field Coach Category 4 US Triathlon Official USAF KC 135 Instructor Pilot - Retired www.FranklyNutritious.com FB Page: https://www.facebook.com/FranklyNutritious Twitter: https://twitter.com/franklynutrient

View Comments (11)

  • Hi.

    I wonder whether the vitamin A value in cronometer is a summary of all different forms, including retinol and beta-carotene. And is the "retinol activity equivalent" in your table the same value as vitamin A (that is, also including retinol and beta-carotene), just different units?
    In my case it is not clear whether I can convert beta-carotene to Vitamin A, so I would like to know the value of retinol itself. So is it right that I have to stick to the retinol value of your table? Is the value for retinol given in all foods of your database? (may be it is not subdivided to the different forms in all cases)

    • Sue,

      SR28 is the current USDA database we have. They state that vitamin A is calculated from vitamin A from individual carotenoids. Vitamin A that is included in the database is individual carotenoids, and retinol combined.

      That is the short version! Here is a link to SR28 and you can see all the details for vitamin A reporting there. It starts at the bottom of page 17. Link: http://www.ars.usda.gov/sp2UserFiles/Place/80400525/Data/SR/SR28/sr28_doc.pdf

      Cronometer breaks it down as SR28 does, and the values are from SR28 as the document explains them. If you are not seeing all the carotenoids, you can go to the profile page and mid page you will see a nutritional targets section. Select the vitamins tab and check the boxes you want to display in the calorie summary section on the diary page.

      Hope that all helps.


  • It is impossible to eat the recommended amount of fruits and vegetables (5 at the lowest end) and not exceed the vit a recommendations by several orders of magnitude. something wrong here, which your explanation doesn't really address. Similarly, I eat about 9 servings of crruit and veg per day (35 grams of fiber) and have never, not even once, reached the daily RDA of potassium. Strange

    • Carolyn,

      The DRI's are easy to exceed, Below is bit on what they are, which you may already understand. Read this also as an example of how the DRI's can confuse with CM use: https://cronometer.com/blog/?p=31517

      The DRI’s (Dietary Reference Intakes) include 2 sets of numbers that serve as goals for nutrient intake. They are the Recommended Daily Allowances (RDA) and Adequate Intakes (AI).

      The RDA’s reflect the average daily amount of a nutrient considered adequate to meet the needs of most people in a population. The AI’s where developed for nutrients that do not have enough scientific data to be given a RDA, which subsequently are given an AI. The Tolerable Upper Limit (TUL) is the recommended maximum of a nutrient someone should consume.

      In Cronometer the Nutrient Targets shows your nutrition targets for the day. Each target has an optional minimum and maximum value. By default, the minimum is set to the Dietary Reference Intake (DRI) value for your body type, and the maximum is set to the Tolerable Upper Limit (TUL), when available. You should strive to get at least 100% of your daily targets from your diet to prevent malnourishment.

      I hope that sorts things out for you.



  • Hi Carolyn,

    I was also shocked by how hard it is to get enough potassium and AVOID overdosing on vitamin A, which can cause terrible symptoms. Using cronometer has made me slowly change over my diet to healthier foods as I strive for 100% of each nutrient and to be in the green zone for the ratios. I eat less greens and carrots and more vegetables that don't have much vitamin A. Turnip has a beautiful nutrient profile. I'm still not reaching my potassium but the recommendation may have something to do with balancing America's high sodium intake so I'm not as concerned about it.

    • Hi Karen,

      As Frank mentioned in the post, vitamin A from vegetable sources (carotenoids) is highly unlikely to lead to vitamin A toxicity. Much like the B vitamins, if you intake excess carotenoids, your body simply excretes them through the urine. This is because your body can 'choose' to digest the carotenoids and convert them to the retinol form of vitamin A, where they would then be stored in the body. If your vitamin A intake is the animal (retinol) form, the body doesn't get to make this 'choice' and will digest as much retinol as you give it, potentially leading to toxicity over time.

  • Thank you Dax, that was an excellent explanation. I did not realize it so now I can eat my greens again!

  • Adult human conversion efficiency of vegetable-based carotenoids is less than 5%, unless one is severely deficient in vit. A, in which case the body will convert carotenoids more efficiently. No one can say how much more efficiently, because studies on conversion efficiency are old and have been done mostly on children who were severely deficient in vit. A.

    Cron-O-Meter should have another slider control in the dialog box you show above that enables users to set the conversion efficiency. The default should be set to 5%.

  • I find the issue with the trans fat reading. I follow a strict plant based wole food oil free diet, yet when I enter my foods I see a trans fat reading. I thought this only occurs in animal product and partially or fully hydrogenated oils.