Vitamin A

Question
I asked you a question a day or two ago. Thanks for your answer!

I'm getting into a very physical sport called Parkour. I've started taking L-Glutamine, Ribose, Cod Liver Oil, Multi Vitamin and Mineral.

Looking at the back of my Cod Liver Oil bottle, it says I'm taking in 4500 IU of Vitamin A per serving. Which I do once daily. I found this article about A overdose.

"-US recommended dietary allowance (RDA) is 5000 IU (2500 IU for children aged 1-4 y).

-Supplements usually are 10,000-50,000 IU per capsule. Fish-liver oils may contain more than 180,000 IU/g.

-Acute toxic dose is 25,000 IU/kg, and chronic toxic dose is 4000 IU/kg every day for 6-15 months."


4000 IU a day is a chronic toxic dose? Firstly, right above that they recommend 5000 IU a day, which makes no sense. Secondly, MultiVitamin, Cod Liver, and my normal diet, I'll be getting around 20,000 IU a day.

I don't get it.

Also, one MultiVitamin of mine has 4200 IU. They say to take 3 a day. Which, supposedly, is 3 times the chronic toxicity rate.

And if IU is a constant unit, how can they write it IU, IU/kg, and IU/g?

So yeah, I'm confused. Please let me know!


Thanks so much!

-Andrew

Answer
The confusion seems to be in understanding the IU vs. IU/kg or IU/g symbols.

IU/kg means the amount of IUs per kilogram of body weight and and IU/g means the amount of IUs per gram of capsule weight.  RDA values are the amount needed only to prevent diseases caused by deficiency.  RDA doesn't mean that's all you should take for optimal health.

If I remember correctly, you weigh 160 lbs. or 352 kg. which means that the chronic toxic level of 4000 IU/kg per day would be in excess of 1,400,000 IU per day.  I hope that clears up your confusion.

Thank you for your follow-up question, Andrew.  I hope that my answer was helpful.

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