Cholecalciferol (Vitamin D3)

Grades and forms of cholecalciferol

Cholecalciferol (vitamin D3) is declared in micrograms, so manufacturers almost always buy it diluted rather than as the pure crystalline substance. A 25 µg label claim equals 1,000 IU at the conversion of 40 IU per µg. The grade you choose depends mainly on the finished format.

• Crystalline cholecalciferol: the pure substance. It is very potent and sensitive to air and light, so it is mainly used to make premixes and diluted grades.
• Oil solutions: cholecalciferol dissolved in a vegetable oil, usually with an added antioxidant. They suit softgel fills and oil drops.
• Dry powders and beadlets: an oil phase containing cholecalciferol, encapsulated in a carbohydrate, gum or protein matrix such as gelatin. They flow and blend like other powders.
• Water-dispersible powders: dry grades built to disperse in water, for drink powders, effervescent tablets and some gummies.

Cholecalciferol is produced from lanolin (sheep wool grease) or from lichen. Source and matrix both decide whether a grade fits a vegetarian or vegan product, so check them on the specification sheet. SoleChem sends that sheet and the certificate of analysis with its quote; they state the declared potency per gram, the carrier and antioxidant composition, and the source. Ask for the grade you need in the quote form.

For the other vitamin D forms and how they are used, see the vitamin D guide.

EU regulatory status

Vitamin D appears in Annex I of Directive 2002/46/EC, and cholecalciferol is listed in Annex II as a permitted form for food supplements. Annex II of Regulation (EC) No 1925/2006 also lists it for addition to other foods. The permitted forms guide explains how these lists work.

Cholecalciferol has no E number and is not used as a food additive. The carriers and antioxidants in diluted grades are a separate matter. Any additive among them must comply with Regulation (EC) No 1333/2008, including its conditions for additives in nutrient preparations; check each one. Whether carrier components must appear in the ingredient list depends on Article 20 of Regulation (EU) No 1169/2011, which exempts carriers used in the quantities strictly necessary and carried-over additives with no technological function in the finished product.

Directive 2002/46/EC requires the label to state vitamin D in the unit given in Annex I, which is µg. The labelling guide covers the full declaration. There is no harmonised EU maximum level yet: member states set their own, as summarised in maximum levels by EU country. For authorised claim wording, consult the EU Register of nutrition and health claims and the health-claims guide.

Formulation notes

Arithmetic. The mass of diluted grade per serving is the label claim in µg, multiplied by (1 + overage), divided by the declared potency in µg per gram. Take the potency from the certificate of analysis, not the product name. The vitamin unit converter handles IU and µg conversions.

Content uniformity. A few micrograms must be spread evenly through hundreds of milligrams of blend. Use a diluted grade, pre-blend it with part of the bulk, and validate blend uniformity.

Stability. Cholecalciferol degrades with oxygen, light, heat and acidic conditions. In solution it also equilibrates reversibly with previtamin D3, depending on temperature. Set the overage from your own stability data; the overage calculator helps with the arithmetic.

Format points.

• Tablets: beadlets protect the vitamin, but high compression force can rupture them. Choose a grade specified for direct compression.
• Softgels: dilute an oil solution into the fill oil and keep oxygen exposure low during filling.
• Gummies: add a water-dispersible grade as late and as cool in the process as the mass allows.
• Effervescent tablets and drink powders: use a water-dispersible grade so the solution stays free of oily residue.

Compatibility. Cholecalciferol is often blended with mineral salts such as calcium carbonate. Transition-metal salts such as ferrous sulfate can accelerate oxidation in premixes, so keep contact time and moisture low.

How it compares to other forms

The vitamin D2 vs vitamin D3 comparison covers sourcing, stability and grade choice in more detail.