Typical dose
200-500 mg of elemental calcium per dose, 1-2 ti...
Oral
Oral safety: low
About this supplement
Calcium citrate (anhydrous) is a calcium salt of citric acid, widely used as a dietary calcium supplement. Unlike calcium carbonate, it does not require stomach acid for optimal absorption, making it suitable for individuals with reduced gastric acidity. The anhydrous form lacks water molecules in its crystal structure. It is considered a highly bioavailable form of calcium, with absorption rates typically around 20-40%, and is often recommended for its good tolerability and reduced risk of causing constipation compared to other calcium salts. It is commonly used to support bone health, muscle function, and nerve transmission.
How much to take
- Typical amount
- 200-500 mg of elemental calcium per dose, 1-2 times daily with meals.
- Suggested range
- 200-1300 mg elemental calcium daily
Potential benefits
Benefits linked to this supplement form:
Things to watch for
Possible side effects linked to this form:
Health goals
Needs and goals this form may help with:
Other forms of Calcium
Compare absorption and active amounts with sibling forms:
Calcium
Calcium 2-aminoethylphosphate
Calcium acetate
Calcium alpha-ketoglutarate
Calcium alpha-ketoisocaproate
Calcium Arginine alpha-ketoisocaproate
Calcium Ascorbate
Calcium Beta-Hydroxybutyrate
Calcium Bisphosphonate
Calcium borate
Calcium borogluconate
Calcium Carbonate
Calcium Caseinate
Slow-digesting milk protein; provides sustained amino acid release.
Calcium Citrate
Calcium Citrate Malate
Highly absorbable calcium source; often used in fortified foods.
Calcium Citrate Tetrahydrate
Highly bioavailable calcium form; does not require stomach acid for absorption.
Calcium d-Glucarate
Calcium Folinate
Calcium Formate
Calcium fructate
Calcium Fructo-Oligosaccharides
Calcium Fructoborate
Calcium fructopyranose borate
Calcium Glycerol Gluconate
Calcium hydroxycitrate
Calcium hydroxyisopcaproate
Calcium hydroxymethylbutyrate
Calcium Iodide
Calcium leucine alpha-ketoisocaproate
Calcium Magnesium Butyrate
Calcium Magnesium Citrate
Calcium magnesium phytate
calcium Octanoate
Calcium Oligofructose
Calcium Palmitate
Calcium pangamate
Calcium Phosphate
Calcium phytate
Calcium Potassium Phosphate Citrate
Calcium pyruvate
Calcium Silicate
Calcium Stearate
Calcium sulfide
Calcium tartrate
Potassium Caseinate
Slow-digesting milk protein; often used in shakes and medical foods.
Sodium Caseinate
Slow-digesting milk protein; common in meal replacements and medical nutrition.
Technical details â–¼
Chemical ID (CAS)
813-94-5
Formula
Ca3(C6H5O7)2
Physical properties
Fine white crystalline powder. Odorless. Slightly hygroscopic. Soluble in dilute acids; slightly soluble in water; practically insoluble in ethanol.
How it’s made
Produced synthetically by reacting citric acid with a calcium source such as calcium hydroxide or calcium carbonate. The resulting calcium citrate is then purified, dried, and milled to the anhydrous form.