Best Calcium Citrate Supplements 2026: Cost per Effective Dose

500 mg of calcium as citrate costs $0.14 to $0.18 at list price for the bottles our buy links open. None of the 5 citrates we price is on a public testing list. Citrate is the form you can take without food; if you take calcium with meals, carbonate gives the same calcium for about half the price.

What calcium citrate costs, best value first

Each of the 5 calcium citrates we price, at the size our buy link opens (Citracal Maximum Plus: the nearest size Vitacost sells): cost per 500 mg of calcium, per serving, and a year at one serving a day, at Vitacost’s list price, checked October 30, 2026.
Product and size	Per 500 mg	A serving	A year
21st Century Calcium Citrate + D3 Petites 200-tablet bottle, list $10.99, 400 mg calcium in 2 tabletsNot on a testing list	$0.14	$0.11	$40
Citracal Maximum Plus 120-caplet bottle, list $13.01, 650 mg calcium in 2 caplets, plus zinc 5.5 mg, copper, manganeseNot on a testing list	$0.17	$0.22	$79
Solgar Calcium Citrate with D3 240-tablet bottle, list $20.85, 1000 mg calcium in 4 tabletsNot on a testing list	$0.17	$0.35	$127
NOW Calcium Citrate with Minerals and D 250-tablet bottle, list $26.49, 600 mg calcium in 2 tablets, plus magnesium 300 mg, zinc 15 mg, copper, manganeseNot on a testing list	$0.18	$0.21	$77

For comparison: Nature Made Calcium 600 mg with D3, a calcium carbonate tablet on USP Verified, costs $0.082 per 500 mg.

When citrate is worth paying for

Citrate does not need stomach acid as much as carbonate does, so you can take it without food (NIH). That helps if you take calcium between meals, or if you have low stomach acid. NIH also says carbonate appears to cause more gas, bloating and constipation than citrate, especially in older adults. Taken with a meal, the two absorb about the same in some studies; a 1999 review of 15 studies found citrate absorbed about 20% better overall. The full comparison.

Per 500 mg, or per serving?

Per serving is what you pay each time you take the label’s serving. Per 500 mg is fairer when strengths differ: a citrate tablet holds less calcium than a carbonate one, because citrate is only 21% calcium by weight (NIH). 500 mg is also about the most your body absorbs well at once, so a bigger serving is best split. How much calcium you need.

Amazon’s price can differ from the list prices here.

Sources

Prices: Vitacost’s list price for every size it sells, checked October 30, 2026 (Citracal, Solgar and NOW’s own stores blocked our reads). We quote no Amazon prices; Amazon is only where the buy links go.
Testing lists: NSF/ANSI 173 and NSF Certified for Sport (our copies), USP Verified (our copy of September 22, 2026).
NIH Office of Dietary Supplements. Calcium fact sheet for health professionals (updated June 22, 2026; read October 12, 2026).
Sakhaee K, et al. Meta-analysis of calcium bioavailability: a comparison of calcium citrate with calcium carbonate. Am J Ther. 1999. PubMed 11329115

Scores rebuilt October 30, 2026.