Is nutrition info completely useless?


#1

Sites like these nowhere state the actual absorption percentage of vitamins and minerals.

For example, endive’s Vitamin K absorption is less than 10%, so it really doesn’t matter how high is its Vitamin K stated in the nutrition data. You would have to eat it in unreasonable amounts to get to 100%.

This is the case across the board.

Why is no one including absorption rates??


#2

There haven’t been particularly many studies into too many bioavailabilities, so it would be quite difficult. Generally the best options for minerals are chelates, but a lot more research is required to be more precise.


#3

I know what that words means, but what does this mean in practical terms?


#4

Essentially, when you take in minerals normally, one of the first steps in order to absorb it after it reaches the stomach is binding it to an amino acid so it forms an electronically neutral complex (isolated minerals are electronically charged). By reacting the mineral to an amino acid prior to consumption, this step is bypassed. This increases bioavailability (the amount that is absorbed) via a number of mechanisms, such as decreasing competition between minerals for amino acids (e.g. calcium and iron) and decreasing phytic acid’s ability to decrease absorption (as the chelates are stable until they encounter an enzyme that breaks them apart). This is why forms of magnesium such as bisglycinate (glycine) or even citrate (citric acid) are absorbed far better than a non-chelated molecule, such as magnesium oxide.


#5

From: http://www.quickanddirtytips.com/health-fitness/healthy-eating/know-your-nutrients/how-much-nutrition-do-you-absorb-from-food?page=2

…the dietary guidelines and recommended intakes for nutrients take into account that you’re going to absorb only a portion of the nutrients in your food. The recommendations represent the amounts you need to take in order to get enough, despite this.