Alert to Users of Calcium Supplements as Antihypertensive Agents Due to Trace Metal Contaminants

Although there are controversies in the role of calcium as an antihypertensive agent, the use of “health food” supplements, such as dolomite and hone meal, is on the rise especially among the older population. One brand of commercial dolomite tablets were investigated for metallic contents such as aluminum (Al), arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb), manganese (Mn), sclemium (Se), and zinc (Zn). Ten randomly selected tablets were weighted, dried, pulverized and low-temperature plasma ashed. An ash aliquot of each tablet was dissolved in 35% Ultrex nitric acid, and after dilution analyzed using a Perkin-Elmer Model 5000 atomic absorption spectrophotometer equipped with an HGA-500 graphite furnace, As-1 autosampler, and PRS-10 printer sequencer. The results (presented as mean wt/g of powder ± 95% confidence limits) are: Al 900 ± 300 μg/g; As 1.3 ± 0.3 μg/g; Cd 0.16 ± 0.04 μg/g; Cr 5.9 ± 1.4 μg/g; Cu 3.0 ± 0.6 μg/g; Pb 1.9 ± 0.5 μg/g; Mn 66 ± 7.0 μg/g; Se 1.6 ± 0.4 μg/g; and Zn 147 ± 88 μg/g. These trace metals could pose health hazards to the public such as lead poisoning, dementia, and hypertension due to cadmium. Also, zinc can potentiate cadmium-hypertensive effects. The need exists to initiate some regulations to limit maximal content of trace metals in “health food” supplements to protect high-risk groups and that sector of the population who use megadoses of such products. Am J Hypertension 1988;1:137S–142S