- Mineral oxides such as Magnesium Oxide or Zinc Oxide are generally considered to be the poorest absorbed form of mineral.
- Mineral Chelates with amino acids have been shown to be better absorbed than other forms of minerals such as sulfates or oxides.
- Iron Bisglycinate has been shown to have much better absorption - twice the ability to be absorbed than the more common ferrous sulfate.
- Chromium Picolinate is much better absorbed than chromium chloride.
- Calcium Citrate is absorbed 22% to 27% better than Calcium carbonate according to a meta-analysis of 15 studies.
- Calcium (in higher doses) interferes with the absorption of magnesium
- High intake of Calcium increases the requirements for magnesium
- Zinc interferes with the absorption of copper.
- Functional cooperation between minerals can occur, ironically between the same minerals that cause absorption antagonism. This is the case with calcium and magnesium. They both provide bone health but should be taken at a different time.
This analysis of mineral supplements was published in the July 2001 issue of Nutrition Science News.
Commentary by Jerry Hickey, R.Ph.
One important example of mineral-absorption antagonism not covered in this review was the inhibition of Iron absorption by both Calcium and by Zinc. It is important to note that although Calcium and Magnesium are needed for activity in the heart, muscles, nerves, and bones, at higher concentrations there is a rational concern that they may inhibit each others absorption and it is also rational that supplementation at higher doses should be taken at separate times. This is maintained in additional sources including Handbook of Vitamins, Minerals and Hormones by R.J. Kutsky, and Trace Elements in Human and Animal Nutrition by E.J. Underwood.
High Dietary Calcium Intake Reduces Zinc Absorption in Humans
In two studies zinc was influenced by calcium. In the first study, high levels of calcium from food or supplements decreased zinc-blood levels significantly in healthy women 59 to 86 years of age. In the second study, high dosages of Calcium decreased the absorption of dietary Zinc by 50% in both men and women aged 21 to 69. These studies appear in the June 1997 issue of the American Journal of Clinical Nutrition.
Green Tea Lowers the Risk of Developing High Blood Pressure
Drinking as little as ? cup of Green tea each day may cut the risk of developing high blood pressure by almost 50%. High blood pressure is the most common form of heart disease and it greatly increases the risk of stroke, heart attack, kidney damage, and according to new research - senile dementia.
Researchers found that men and women who drank green tea daily for at least a year cut their risk of developing high blood pressure by 46% if they drank 4 to 10 fluid ounces per day or up to 65% if drinking more than 20 ounces per day. The study appears in the July 26th issue of the Archives of Internal Medicine.