What is vitamin A?
Vitamin A is the name for retinol and related compounds (retinal, retinoic acid and their esters). Animals cannot make vitamin A from scratch, but most species can convert plant carotenoids, mainly beta-carotene, into vitamin A in the intestinal wall. Cats are an exception and need preformed vitamin A.
Retinol itself is unstable, so the feed industry uses its ester, retinyl acetate, which is further protected by antioxidants and a gelatin or starch matrix to form beadlets. By definition, 1 IU of vitamin A corresponds to 0.344 µg of retinyl acetate (0.300 µg of retinol).
What does vitamin A do in animal feed?
- Vision: retinal is part of rhodopsin, the light-sensitive pigment of the retina; deficiency causes night blindness.
- Epithelial tissue: maintains the skin and the mucous membranes of the respiratory, digestive and reproductive tracts, which act as a first barrier against infection.
- Immunity: supports normal immune responses; deficient animals are generally more susceptible to disease.
- Reproduction: important for fertility, embryo development and, in breeding animals, for the vitamin status of offspring.
- Growth and bone: needed for normal bone remodelling and growth in young animals.
- Ruminants: grazing animals obtain carotene from green forage, while animals on stored forage, dry pasture or concentrate-rich diets rely more on supplemental vitamin A.
Forms and sources of vitamin A
- Retinyl acetate beadlets: the standard feed form, typically at 500,000 IU/g (often called vitamin A 500) or 1,000,000 IU/g (vitamin A 1000), designed to resist heat, pressure and oxidation during premix storage and pelleting.
- Other esters: retinyl propionate and retinyl palmitate are also used, more often in liquid or special applications.
- Beta-carotene: provitamin A found in green forage and carrots; the conversion efficiency differs between species.
- Natural feed ingredients: cereals and oilseed meals contain little vitamin A activity, which is why supplementation is standard in compound feed.
How is the vitamin A supply assessed?
Nutritionists set vitamin A levels in IU per kilogram of feed according to species, age, production stage and the expected stress or disease pressure. They also allow for losses during premix storage, pelleting or extrusion, and for the carotene contribution of forage in ruminant diets. Vitamin A is stored in the liver and excessive intake over long periods can be harmful, so inclusion should follow recognised recommendations, the product label and local regulations.
Stability and quality criteria
- Declared activity (IU/g), confirmed by analysis, and its retention over the shelf life.
- Beadlet integrity: resistance to pressure, heat and moisture during mixing and pelleting.
- Sensitivity to oxygen, light, heat, moisture and trace minerals: premixes should be kept cool, dry and in closed packaging, and used within their shelf life.
- Interaction with choline chloride and free trace minerals, which can accelerate vitamin A loss in concentrated premixes.
- Particle size for even distribution, and a certificate of analysis (CoA) for each lot.
CTF Premix and vitamin A
Vitamin A in the form of retinyl acetate can be included in CTF Premix's vitamin, vitamin-mineral and custom premixes according to the customer's formulation. We take stability into account when choosing carriers and when combining vitamins with trace minerals and choline. Production takes place at our Ankara facility under ISO 9001:2015 and GMP; each lot has a certificate of analysis and can be traced on the batch verification page of our website.
This page is for general information. Inclusion rates and product choice should be decided with a nutritionist, taking into account the species, the feed formulation and the applicable regulations.