I would like to mention that chelation can be used in two ways:

1) To improve absorption of mineral supplements.

2) To detoxify heavy metals.

The chelates used are different. In the first case, the ligand shouldn't bind
too strongly to the mineral (otherwise the mineral wouldn't be assimilated), and
in the second case, the ligand should be excreted via the kidneys, still bound
to the metal.

As for use #1, the opinions are divergent. Using chelating agents allows to
reduce the amount of mineral supplements, but one may wonder if the improved
absorption is worth it (usually, +100%-300%, depending on the pair
mineral-ligand), especially if the ligand is synthetic.

Note: I read in another book that iron in heme-form (like in meat) has a 23%
absorption rate, whereas iron in non-heme form (like in vegetables) is poorly
absorbed (3%). However, ingesting 75 grams of vitamin C at the same meal
multiplies the absorption by 5 (approximately).


Concerning use #2, chelates commonly used are synthetic, like "BAL" for mercury.