Measurement of simple pharmaceuticals & dietary supplements

[klugesmith]

This seems like the least wrong subforum for a chemistry topic.

For many years I've ingested a few pills each day, from a short list that recently includes "Calcium supplement".  Just finished a bottle of 500 pills, and opened a new one.
The label says 600 mg, and I wondered if that's the weight of calcium or that of calcium carbonate.
For reference, my daily iron supplement (since I donate blood) is labeled with weight of ferrous sulfate.
Water hardness measurements (in ppm, grains/gallon, etc) indicate equivalent weight of calcium carbonate, even if no carbonate is present.

Weighing some pills gave the answer.   Looks like each pill is made with 1.5 grams of CaCO3, which includes 0.6 grams of Ca.
In 16 months I ate 750 grams of chalk, costing more than $20.
The same money could buy 750 kilograms of crushed limestone at a rockery!

[rikkitikkitavi]

I dont think you should try to ingest 750 kgs of crushed limestone , even over a period of 16 months...

I would definately mess up your stomach (neutralising) , make you burp and fart immensly and likely also congest your intestines apart from any Calcium overdosing.

I