Taking too much of an ethylenediaminetetraacetic acid supplement, such as EDTA Mega Plus, can result in kidney damage, low calcium levels and even death, states WebMD. EDTA also exacerbates heart rhythm problems, cause low potassium levels and worsens liver disease and hepatitis.
People who take insulin to control diabetes must not take EDTA because it also decreases the amount of blood sugar in the body, states WebMD. Those who take warfarin to slow blood clotting must not take EDTA because it reduces the effectiveness of the drug. While the manufacturer of EDTA Mega Plus claims that the supplement reduces plaque in the circulatory system, WebMD states that it is likely ineffective for treating coronary heart disease.