T Nation

Recommended Daily Intake


Do you put much stock in the RDIs made by the Food and Drug Administration? Are they minimums? Maximums? What is the range beyond them that would be optimal and what would be detrimental?

Like currently I am consuming over 200% of my daily values of vitamins and minerals except for iron (98%) and vitamin d (43%). I am considering supplementing in each, but I don't know if I should worry about it with iron (since I am close to 100%) for instance.

Then again, I'm consuming about 3200 calories so should I be taking in over 150%?

The whole RDI thing seems quite nebulous to me...


I think it really depends on the specific vitamin/mineral in question.

For vitamin D I'm sure most will tell you that you should supplement. http://www.tmuscle.com/free_online_article/sports_body_training_performance_nutrition/d_is_for_doping is a recent article by Chris Shugart on the benefits of vitamin D and there was a pretty recent discussion about Vitamin D supplementation in this forum as well.


They're typically minimums, and mostly outdated. Being constantly active and training your body also contributes to your nutritional needs.

If you read the recent Vitamin D (D is for Doping) article, it's recommended to get about 5000% the RDI/RDA which had been set pretty low. If you do a bit of research on each nutrient, you should be able to find some information on where the RDI is, what may be better based on the research done since the number was set, and perhaps some factors that may contribute to a greater need.


Hell no, the RDI's are the bare minimums for normal function. You don't fall in the "normal" category if you lift heavy and train hard to gain muscle or get stronger.


Those are rather conservative amounts that the governments lists for the RDI. I probably take in 10x or more of most vitamins' RDI, and I know that, for a lot of vitamins, you can go a lot higher.


The RDA (Recommended Dietary Allowance) is a reference to meet daily nutritional needs of about 97%-98% of the population. It is based upon the Estimated Average Requirement (EAR) which is the average amount of a nutrient known to meet the needs of 50% of similar population. It is a starting point for other values.

The RDA is set higher than the EAR. I would say for most things go above the RDA. If you are a male, you do not need to supplement with extra iron as too much can be bad. Women on the other hand might need to (because of blood loss). As far as Vit. D look at this: http://www.tmuscle.com/free_online_article/sports_body_training_performance_nutrition/d_is_for_doping


There is no general rule covering them all: each one varies.

Unless female, do not supplement with iron.

On the other hand, with Vitamin D the RDA is much lower than an optimal value. 4000 IU per day would be good, or 5000 if the product you buy happens to be that dosage. (For some individuals 6000 or 8000 IU can be provably better, by blood levels, than 4000 IU per day, but my point is that 4000 IU per day is far better than what the RDI is, and is generally safe.)