It was 25 years ago that I was told by my nutrition teacher that Vitamin A works even better than Vitamin C does for fighting or preventing common colds and flu when taken in high doses (up to 25,000 IU per day).

This made a big impression on me because I had heard that you weren’t supposed to do high dosing with Vitamin A, and it changed how I prepared for cold and flu season thereafter. Vitamin A is a very strong antioxidant, and it can be taken in high doses for short durations–up to two weeks–with no toxic effects on the ordinary person.

Vitamin A is a great nutritional supplement to take at high doses (25,000 IU) at the first hint of a common cold.

Vitamin A is also a great supplement to take daily at regular doses (1500-3000 IU per day) for tissue support, eye health, and healthy skin maintenance support.

High-dose vitamin A is not good for women who are about to become pregnant or who are pregnant (because high doses can cause birth defects). 8000 IU supplementation would be the safest high dose for a pregnant woman. That being said, a pregnant woman who eats a healthy diet, might find 1500-3000 IU’s in supplementation to be just fine. (Vitamin A, whether from food or supplements IS needed during pregnancy for a healthy baby.)


Antioxidant Vitamin A

Vitamin A is an antioxidant. Antioxidants are very beneficial to our tissues: they help clean up the mess that free radicals make. Destructive free radical activity is happening all the time throughout our cells. Free radical activity worsens with exposure to toxins and radiation. But as long as the antioxidant activity exceeds the free radical activity, then the health of the cells can be maintained.

One of the best online summaries of the multiple benefits of Vitamin A—including more on its antioxidant properties–is found at The Linus Pauling Institute of Oregon State University.


Is Vitamin A Toxic?

What about Vitamin A toxicity? The conventional understanding of Vitamin A is that it is toxic at high doses. It is true,…with a caveat. You would not want to take the fat-soluble or “preformed” type of Vitamin A (otherwise known as retinol, retinal, and retinoic acid) in high doses for longer than two weeks at a time. What are the options for dosing?

  1. The average person can take the 25,000 IU per day of preformed/fat-soluble regular Vitamin A for about two weeks maximum to bolster your reserves of this important nutrient. It does not become toxic unless taken at high doses for long periods.
  2. Or you can take Vitamin A that is water-soluble to avoid Vitamin A toxicity. This type of “pro” Vitamin A is known as beta carotene or carotenoids. It is called pro-Vitamin A because the body can turn it into the more active or stronger Vitamin A. It too can create a side effect if taken for prolonged periods at high doses, and that is an orange or yellow color to the skin, particularly the palms of the hands. If this happens, you are definitely taking too much. My opinion on supplementation, in general, is: More is not better–unless a short term for specific uses. Otherwise, a quality supplement can be taken in moderate doses with good effect.
  3. Therefore, the last option is to take a “maintenance dose” (3000-8000 IU) of preformed or pre-vitamin A (or a mixture of both) per day, match your dosing to your goals and needs.


Genetic Repair Effects and Vitamin A

Vitamin A is widely known as a powerful antioxidant; however, it is less known for its ability to affect mitochondrial and DNA genetic repair. Vitamin D and Vitamin A work together to repair the genes, and both vitamins must be present to get the genetic repair effects (an effect that is more widely associated with Vitamin D).

It is the presence of the Vitamin A within Vitamin D metabolism that makes the Vitamin D have genetic repair potential.

(This I learned in my most recent continuing education class sponsored by Aduco.) Said yet another way because it is a bit confusing….the Vitamin D can do a lot without Vitamin A. But with Vitamin A, the Vitamin D can also do the genetic repair.

Vitamin D goes through various processes of metabolism, and after it gets to the kidney, the Vitamin D connects up with Vitamin A. This is where the two get together, enabling them to repair the DNA and RNA ladders throughout the body in the places where the DNA has twisted in on itself. Vitamin D, activated by the presence of Vitamin A can also repair the mitochondria.


Vitamin A Factoids

Other nutrients are needed to obtain the full benefit of your Vitamin A. Whether you supplement with Vitamin A or just get it through your food, other nutrients like zinc and iron act as cofactors to optimize the benefits of Vitamin A. For discussion on zinc, you can go to The Linus Pauling Institute.

It’s a factoid that zinc helps activate an enzyme that makes Vitamin A work fully.

Another Vitamin A factoid that not many know is that iron deficiency and Vitamin A deficiency often go hand in hand. To supplement with Vitamin A can help iron reserves over time.


Types of Vitamin A Supplements

At The Better Energy Shop, we carry a number of types of Vitamin A supplements that we are proud to offer both in our online and in our brick and mortar shop:

  1. Standard Process Cataplex A is a food-sourced Vitamin A product. Because of that, Cataplex A is, therefore, a beta carotene (or pro-Vitamin A) product. The great majority of Standard Process supplements are true food concentrates. These are not the misleading “food-based” supplements (i.e. synthetic vitamins bonded to a food base) that many other supplement companies tout. There is a big difference between concentrated food and synthetic vitamins bonded to food in a lab. It’s okay to take either type, depending on preference and needs, but wouldn’t you like to know what it is that you are purchasing?

Two aspirin-sized Cataplex A tablets are 1500 IU.

Cataplex A

  1. Apex Energetics AD-Pro is a Vitamin A plus Vitamin D blend product that requires just one soft gel to get a higher dose of 8000 IU of Vitamin A, as well as 3000 IU of Vitamin D daily. AD-Pro has a higher amount of the preformed A, which is a stronger version of Vitamin A–relative to the amount of pro-Vitamin A carotenoid within AD-Pro. This product was designed by Apex to be your one-a-day in perfect ratio for vitamin A and D needs for those who want a little more A.



  1. Apex Energetics ADEK-Pro is another blend product that offers an array of antioxidants so you can get the benefits of each type of nutrient, plus the Vitamin K that allows you to get your Vitamin D working even better for your bone health. This product is great for a person who does not want to have, or cannot have high dosing of Vitamin A and is looking for general antioxidant, tissue, bone, and gut health support.


Looking to do vitamin unit conversions such as micrograms to IU’s (International Units)? Use this converter.

Consult with your health care provider if you are wishing to take vitamin supplements and are also on medications. Consult with your medical practitioner if you wish to take vitamin A supplements and you have liver or kidney disease. If you are pregnant or seeking to become pregnant or are breastfeeding, seek advice from your health care provider for supplement dosing.

© Sylvia Skefich, D.C., 2020