Ground animal bone, usually bovine, sold as a calcium supplement in the form of hydroxyapatite with the bone matrix retained. It is distinct from purified calcium salts, which are made chemically.
Bone meal is the reason lead in supplements became a public issue. Bone accumulates lead over an animal's lifetime, and analyses from the 1980s onward repeatedly found bone meal calcium products containing lead at levels of real concern, prompting regulatory warnings and advice against giving it to children or in pregnancy — the two groups most vulnerable to lead and most often targeted by calcium marketing. Testing has improved and the better products now assay for it, but the underlying biology has not changed: the raw material is the tissue where lead is stored. The efficacy case for microcrystalline hydroxyapatite over ordinary calcium salts, meanwhile, rests on small studies and is not established.
Sold as
Bone meal powder, Microcrystalline hydroxyapatite tablet, Capsule, Whole-bone calcium blends
Standardised to
Elemental calcium content; the meaningful additional figure is a measured lead and cadmium assay, which many products do not publish — a product without this marker may not resemble what was studied.
Also known as
Bone powder, Microcrystalline hydroxyapatite (MCHC), Bovine bone calcium, Ossein hydroxyapatite
Regulation: Sold as a dietary supplement in the US with no pre-market efficacy or safety review. Health authorities have warned against bone meal as a calcium source for children and in pregnancy because of lead content, and some jurisdictions restrict bovine bone sourcing on prion-control grounds.
What the research used
The amounts, forms and durations published trials of Bone meal actually administered.
These are the amounts published trials administered — not a recommendation, and not a dose to copy. Trial participants were screened, supervised and given a characterised preparation. What is in a retail bottle is frequently not what was studied, and the amount that suits one person is not general advice.
Studied for Calcium supplementation
500–1200 mg
Limited
Elemental calcium as hydroxyapatite, daily or divided
Doses match general calcium supplementation practice rather than any trial of bone meal specifically. Splitting doses is standard because calcium absorption falls above roughly 500 mg at once.
This is general information about food, not medical advice. It cannot diagnose, treat or replace guidance from a clinician who knows your history.
When it was taken
Each window says whether a trial compared it against an alternative, or whether it is convention and pharmacology. Most timing advice is the second kind.
Each timing below was actually compared against an alternative in a trial, which is unusual.
🔀Split through the day
Moderate
Calcium absorption declines as single doses rise above about 500 mg, which is measured pharmacology for calcium generally rather than a comparison run on bone meal.
Timing was tested. A trial compared this window against another and reported a difference.
The evidence in depth
Best supported: Not enough
What each association actually rests on, and the papers behind it. A rating describes the state of the research, not how promising the supplement sounds. How we rate evidence.
Calcium intake matters for bone, and small studies of microcrystalline hydroxyapatite report bone density effects broadly comparable to other calcium sources, with some suggesting an advantage. The trials are small and old, and the case that bone-derived calcium outperforms a purified salt is not established.
Not enough evidence. Not enough human research to say anything useful yet.
No source is attached to this association yet, so it is rated not enough evidenceby default. It is listed because people commonly ask about it — not because there is evidence for it.
Things to know
Interactions, contraindications and dose limits, most serious first. Concentrated extracts interact with medication in ways the whole plant does not, so this section carries more weight here than it does on a food page.
Worth knowing
Lead contamination
Bone is where lead accumulates in a living animal, and analyses of bone meal supplements have repeatedly found meaningful lead content. Lead has no safe level in children, and public health authorities have specifically advised against bone meal as a calcium source for children and in pregnancy. Any product without a published heavy metal assay should be regarded as an unknown exposure.
Worth knowing
Bovine sourcing and prion controls
Bovine bone products sit within the material categories that transmissible spongiform encephalopathy controls were built around. Sourcing from countries with documented controls, and traceability of the herd, is the relevant safeguard, and it is not something a label claim substitutes for.
Too much
Calcium excess has its own risks
High supplemental calcium is associated with kidney stones and, in some analyses, with cardiovascular risk, and it interferes with iron and zinc absorption. Total intake from food plus supplements is what matters, and most people get more from food than they assume.
Interaction
Reduces absorption of several medicines
Interacts withTetracyclines, quinolone antibiotics, levothyroxine, bisphosphonates, iron supplements
Calcium binds tetracycline and quinolone antibiotics, levothyroxine and bisphosphonates, substantially reducing their absorption. These need to be separated by several hours.
In the food catalogue
The whole-food form, where one exists. The evidence for a concentrated extract rarely transfers to the food, or the other way round — these are cross-links, not equivalents.