Vitamin A Palmitate (Retinyl Palmitate)

Vitamin A palmitate, CAS 79-81-2, is all-trans-retinyl palmitate: retinol esterified with palmitic acid, molecular formula C36H60O2 and molecular weight 524.9. Esterifying the alcohol is what makes vitamin A usable in industry — free retinol is too fragile to survive a fortification line, while the palmitate ester holds its potency in oil, in a dry matrix and in a dairy or edible-oil matrix. It is the ester used to restore vitamin A to reduced-fat milk after the fat has been removed, and the ester most food and supplement manufacturers standardise on. Vitamin A contributes to the normal function of vision and to the maintenance of normal skin, and it is described here purely on that established nutrient function and on its composition. Potency, not weight, is the trading unit. The pharmacopoeial oil concentrate is specified at a minimum of 1,700,000 IU per gram — the familiar 1.7 MIU/g grade — and lower oil strengths are produced by dilution in refined vegetable oil to a customer's target. Dry forms are supplied as beadlets, most commonly 250,000 IU/g in a cold-water-dispersible build (equivalent to 75,000 micrograms of retinol per gram) and 500,000 IU/g where a tighter dose is wanted. The conversion to work from is fixed: 1 IU of vitamin A equals 0.30 micrograms of all-trans-retinol, which is 0.55 micrograms of retinyl palmitate, so one microgram of the palmitate is about 1.82 IU. Every grade is antioxidant-protected, typically with dl-alpha-tocopherol, ascorbyl palmitate, BHT or BHA; an unstabilised concentrate is available where the buyer prefers to add its own system. Two commercial points decide which grade a buyer can actually use. The first is the beadlet matrix: dry vitamin A is built either on gelatin — bovine or fish, with sugars and starch — or on a vegan matrix of modified maize starch and acacia. Fish gelatin is a declarable fish allergen and bovine gelatin ends any vegan or vegetarian claim, so the matrix must be specified at enquiry rather than assumed. The second is the carrier oil in liquid grades: a refined soybean oil carrier triggers a soy declaration in several markets, and sunflower, maize or MCT oil should be nominated where a soy-free label is required. The retinyl palmitate molecule itself is synthetic and contains no animal-derived material; the diet and allergen status of the finished article is set entirely by the matrix and carrier, both of which Thovek states on the specification sheet.