Calcium

Single-ingredient calcium reference formula at 1,000 mg of elemental calcium per serving, developed as a two-tablet serving, capsules or a powder.

Calcium is a reference formula for brands building a single-ingredient calcium product at a default amount of 1,000 mg of elemental calcium per serving. Calcium is the only active ingredient, and the development work is dominated by salt weight: a gram-level mineral load decides the tablet count, the capsule count and the texture of a powder.

Tablet is the lead format, with the default amount split over two tablets as on the reference label, and the capsule and powder versions use the same calcium amount with their own salt choices. A 500 mg option sits beside the default for brands that prefer a one-unit serving.

Ingredient Composition

IngredientPer ServingRaw Material FormAlternative Form (same amount of active)
Calcium1000 mg (default amount)Calcium carbonate, specified on elemental calcium content; 1,000 mg calcium per servingCalcium citrate for powders or for a different salt profile, with the input recalculated to 1,000 mg of elemental calcium

Amounts are stated as mg of elemental calcium (Ca, 40.08 g/mol; PubChem CID 5460341). Calcium content by weight follows from the anhydrous molecular weight: calcium carbonate 40.0% (CID 10112, 100.09 g/mol) and calcium citrate 24.1% (CID 13136, 498.4 g/mol, three calcium atoms per formula unit). Hydrate state and assay of the purchased salt are set with the supplier.

Intended Benefits & Formula Rationale

This formula is designed for products positioned around daily calcium intake and bone nutrition. Calcium is included as the only active so that the salt, the amount and the unit count can be set without interaction with other actives.

Intended Benefit DirectionKey IngredientsFormulation Rationale
Daily calcium intakeCalciumIncluded because the 2011 Institute of Medicine report sets calcium Recommended Dietary Allowances of 700 to 1300 mg per day for ages one year and older [1]. Evidence: Referenced
Bone nutritionCalciumPositioned around skeletal nutrition because that report concluded that the evidence supports a key role of calcium in skeletal health [1]; a later review of trials concluded that calcium supplements do not prevent fractures in community-dwelling adults [2]. Evidence: Contested

A single stated amount lets the brand choose the number of units per serving. The two reviews do not agree on what supplemental calcium does for the skeleton, so the amount, the claims and the target market are brand decisions reviewed per market.

Available Formats

The calcium reference formula is built for tablet, capsule and powder versions; counts per serving are design choices that the brand can adjust.

FormatUnitPer ServingPack SizeOther Ingredients (typical)Suitability
Tablet2 tablets1000 mg120 tablets (60 servings)Cellulose, croscarmellose sodium, stearic acid, magnesium stearate, coatingLead format; matches the two-tablet reference label
Capsule4 capsules1000 mg240 capsules (60 servings)Flow agent, capsule shellFour-capsule serving for brands that avoid tablets
Powder1 stick pack1000 mg30 stick packsDiluent, acidulant, sweetener, flavorDrink mix; texture is the main task

Raw Material Input & Fill (Design Estimate)

Design estimates. The input is the calcium amount divided by the calcium content of the salt at an assumed 100% assay: calcium carbonate at 40.0% for tablets, capsules and powder, so 1000 mg of calcium needs about 2,497 mg of salt per serving; calcium citrate at 24.1% would need about 4,145 mg.

FormatRaw Material Input per UnitDesign FillBalance for ExcipientsVerification Before Scale-Up
Tablet1249 mg per tablet (2 per serving)1450 mg tablet weight201 mgCompression behavior, hardness, disintegration, content assay
Capsule624 mg per capsule (4 per serving)680 mg per capsule56 mgFill weight variation, flow, content assay
Powder2497 mg per stick4500 mg per stick2003 mgDispersion in water, grittiness, content assay

Gummy and softgel versions are separate projects, because a calcium load of this size does not fit them without a smaller amount per unit.

Formulation Considerations

Salt weight and unit count. About 2.5 g of calcium carbonate per serving is the reason for two tablets or four capsules. A smaller serving of 500 mg halves the count, and the unit count is fixed together with the brand’s preferred pack.
Carbonate or citrate. Calcium carbonate carries the most calcium per gram of salt, which keeps units small. Calcium citrate carries less, so the same 1,000 mg needs about 4.1 g of salt, but it is the alternative when a brand wants a different salt profile for powders or for intake without a meal.
Chalky texture in powders. Calcium carbonate is an insoluble salt, and in a drink mix it shows as grittiness. Particle size, a suspending system and an acidulant are tested in the powder version before the grade is fixed.
Safety review of the amount. A review of trial evidence reports that calcium supplements commonly produce gastrointestinal side effects, increase the risk of renal calculi, and are associated with a 10–20% higher risk of myocardial infarction in meta-analyses of adverse events [2]. The label wording and the dose limit for each sales market are reviewed before a product is developed.

Customization Options

Brands adjust the amount per serving, the calcium salt, the unit count and the format.

ParameterRangeNote
Amount per serving250, 500, 600 or 1000 mgOptions for the brand; unit count scales with the tier
Calcium saltCarbonate or citrateInput recalculated to elemental calcium; citrate needs about 1.7 times the salt weight
Units per serving1 to 4 tablets or capsulesSet by the amount and the salt
FormatTablet, capsule or powderGummy and softgel are separate projects
Add-onsVitamin D, magnesium, vitamin KA second active reshapes the tablet weight and the stability plan

The pilot run confirms tablet hardness and disintegration at the full salt load, capsule fill weight and flow, powder grittiness, and the content assay of the first units against the labeled amount of calcium.

Flavor Options

FormatSuggested FlavorsWhy
PowderVanilla, lemon, strawberryMild profiles cover the chalky note of an insoluble salt

Technical Status & Data Sources

ItemStatusDetails
Reference formulaNIH DSLDThe ingredient and amount come from a labeled product in the NIH DSLD (1000 mg on the label of CF001015, a two-tablet serving; example DSLD labels 6996, 11102, 11104). The label names the ingredient as calcium; calcium carbonate is set as the form.
SpecificationSet in formulationCalcium carbonate, 1,000 mg elemental calcium per serving; assay, particle size and heavy-metal limits and method are fixed with the supplier. Unit size, fill weight and stability are set in formulation.
Data sourceNIH DSLDDSLD v9.4.0, downloaded 2026-01-10: 50,824 reference formulas merged from on-market labels with complete ingredient amounts. Counts show how labels are distributed.
Market reviewPer marketDose limits, labeling and claims are reviewed for each sales market before a finished product is developed.
ReferencesSources[1] Ross AC, Manson JE, Abrams SA, et al. The 2011 report on dietary reference intakes for calcium and vitamin D from the Institute of Medicine: what clinicians need to know. J Clin Endocrinol Metab. 2011;96(1):53-8. DOI · PubMed<br>[2] Reid IR. Calcium Supplementation- Efficacy and Safety. Curr Osteoporos Rep. 2025;23(1):8. DOI · PubMed

Related products

OEM/ODM Development Inquiry

Essencefield supports custom supplement formulation and OEM/ODM development, including ingredient selection, dosage adjustments, delivery formats, flavors, packaging, and commercial supply. Submit your project requirements below to explore customization options, sample development, and manufacturing solutions tailored to your brand and target market.