Dicalcium Phosphate vs. Calcium Citrate
Among 5,062 on-market calcium products with an identifiable primary form, 24.2% use Dicalcium Phosphate (1,226 products) and 20.3% use Calcium Citrate (1,027).
| Dicalcium Phosphate | Calcium Citrate | |
|---|---|---|
| Quality tier | Unrated | Tier 1 |
| Calcium by weight | 23.3% | 21.1% |
| Share of market | 24.2% | 20.3% |
| On-market products | 1,226 | 1,027 |
| Median declared dose | 98.13 elemental mg middle half: 50–166 | 125 elemental mg middle half: 50–400 |
| Most common brands | The Vitamin Shoppe, DC, Mason Natural | Bluebonnet, Pure Encapsulations, Bariatric Advantage |
Doses are declared per serving in elemental mg. “By weight” is the share of the ingredient that is the nutrient itself (e.g. elemental magnesium in a magnesium salt).
Why Dicalcium Phosphate is unrated
No specific human comparative bioavailability study vs carbonate/citrate was verified.
Source: none located (no human comparative absorption study of dicalcium phosphate vs carbonate/citrate found)
Why Calcium Citrate is tier 1
Meta-analysis of 15 studies (184 subjects): absorption significantly higher than carbonate by ~20-27% (27.2% fasting, 21.6% with meals). Citrate absorption is generally considered less dependent on gastric acid (general pharmacology, not from the abstract).
Source: Sakhaee K et al. 1999, PMID 11329115