If you’re worried about osteoporosis (and you should be, it’s a killer, albeit indirectly through hospitalisation and the potential for acquiring lethal infections on a prolonged medical incarceration), you may have been considering calcium supplementation. Fine. But, , stick to purified supplements (calcium carbonate or calcium citrate, for those taking proton pump inhibitors for GERD, such as omeprazole).
Because ‘natural’ does not necessarily mean good. Calcium carbonate preparations made from oyster shells or bone meal can be high in lead or other toxic heavy metal elements that are detrimental to (bone) health. Load-bearing exercise is also a very useful combatant to prevent loss of bone mass as one gets older.
If you’re worried about “synthetic” being bad for you compared to “natural” then take a look at the chemistry. Pure calcium carbonate dissolved in your stomach is exactly the same regardless of its source, but those “natural” supplements are generally not pure, despite what your naturopath might claim. This has, of course, been known for several years, but my recent foray into the world of personal proton pump inhibition led my neurotic brain to seeking out information on side-effects of omeprazole.
Kim, M., Kim, C., & Song, I. (2003). Analysis of lead in 55 brands of dietary calcium supplements by graphite furnace atomic absorption spectrometry after microwave digestion Food Additives and Contaminants, 20 (2), 149-153 DOI: 10.1080/0265203021000053588