Multivitamin and mineral capsules are one of the highest-volume categories in private-label supplements, and also one of the hardest to get right. A capsule has a fixed volume, and every additional nutrient competes for space, stability and flow. This guide covers the decisions a buyer should make before briefing a manufacturer.
Why capsules for a multivitamin
Capsules hold powders, granules, pellets and small oil fills without heat or high compression, so heat-sensitive vitamins such as vitamin C and the B group survive better than in a pressed tablet. Two-piece hard capsules come in standard sizes (3, 2, 1, 0, 00 and 000); size 0 or 00 covers most adult formulas. Softgels suit oil-based, fat-soluble nutrients — vitamins A, D, E and K, CoQ10 and omega oils — because the fill itself is an oil.
Tablets still win on cost per dose at very large volumes, and gummies win on consumer appeal for chewable and children's lines. Many brands now list the same formula in two formats to test which one converts; see our gummies vs capsules comparison.
Choosing nutrient forms
The panel may read "magnesium 100 mg", but the salt form decides absorption, cost and capsule size:
- Magnesium — oxide is inexpensive but bulky; citrate and bisglycinate are better absorbed and carry less elemental weight, so they fit a smaller capsule.
- Calcium — carbonate delivers more elemental calcium per gram; citrate is gentler but bulkier.
- Iron — bisglycinate and fumarate are common; sulphate is cheap and harsher.
- Zinc — picolinate and citrate versus oxide, again a trade-off between elemental content and tolerance.
- Vitamin B12 and folate — methylcobalamin and methylfolate cost more than cyanocobalamin and folic acid, and are frequently specified by buyers.
Salt forms also change flow behaviour. A sticky or static-prone blend will not run cleanly on a capsule filler, so formulators add small amounts of anti-caking and glidant excipients (magnesium stearate, silicon dioxide) and may granulate the blend first.
Sizing, fill weight and overages
Start from the nutrition panel, convert each nutrient to its elemental weight, then add the excipients required for flow. That total sets the capsule size. Two practical warnings:
- Overages. Vitamins degrade in storage, so a small overage is added at manufacture to remain above the label claim at the end of shelf life. That overage has to stay within the destination market's rules.
- Fill capacity. A size 0 capsule holds roughly 500–700 mg of a typical blend, depending on bulk density. If the formula needs 1,200 mg per daily dose, you either split it across two capsules or move to tablets or powder.
Stability and shelf life
Moisture, oxygen and light cause most potency loss. Practical controls include an induction seal or desiccant in the closure, opaque or amber packaging for light-sensitive actives, and a 24-month shelf life supported by real-time and accelerated stability data rather than assumption. Ask for a COA with every batch and a stability protocol — not only a specification sheet.
Labelling and market compliance
Each destination market sets its own panel format and permitted nutrient forms. The United States uses Supplement Facts with % Daily Value; the European Union uses the Nutrition Reference Value and a positive list of permitted vitamin and mineral forms; Gulf and ASEAN markets add their own registration steps. Confirming the panel, the nutrient forms and the permitted wording before artwork is printed avoids a reprint.
Private label: MOQ, sampling and lead time
Multivitamins are usually the easiest category to trial because they use standard capsule sizes and standard bottles. A practical starting point with a manufacturer that supports small batches is MOQ 500 units per SKU, samples in 3–5 days, production shipped within 7 days and a COA with every batch. That lets a new brand validate one formula before committing to a full range.
How Haiyue Shengda works
We produce multivitamin and mineral capsules, tablets, gummies, powders and drops in our own 5,000+ m² factory with 7 production lines and 34 machines, under FDA facility registration, HACCP, cGMP-compliant production and ISO 22000. Custom formulas and outer-packaging design are free, with the first sketch delivered in about two hours. See capsules and softgels for available formats, read our FAQ, or contact us — we reply within one hour on working days.