Re: iron supplement?

Plant sources also contain vitamin C, which increases the absorption of iron so it counters the blocking action of the calcium. Calcium supplements are a different story.

Broad statements should be clarified if one is denouncing an essential element and if one is aware of how to supplement properly calcium can be a great benefit for those who suffer from a calcium deficiency.
Vitamin c or any organic acid helps both calcium and iron be assimilated, Vita C has no function in blocking calcium, only helping it be utilized properly.