A Guide to Equine Feeding and Maintenance


A good rule of thumb is to take care of vitamins A, B, C, D and E

The liver of a horse produces vitamin C, while the bacteria in the large intestine produce most of the vitamin B if the intestine is functioning properly and the feed is nutritious. The performance of the intestine can be impaired, in which case vitamins should be provided through complimentary feed. The need of vitamins may increase due to changes in diet, strain, changes in environment, pregnancy, rapid growth, extensive training and racing as well as other stress factors.

The vitamin recommendations for a horse vary depending on whether the vitamins are meant to prevent a certain deficiency in the diet or whether the recommended vitamins are designed to fulfill all the needs of the horse. Vitamin requirements are unique for every horse. The vitamin recommendations for every country vary to account for the local climate and soil. In the Nordic countries the vitamin requirements fluctuate greatly between seasons. As the year progresses deeper into winter a horse will retrieve less and less vitamins from hay and oats. This means, special attention should be given to vitamin requirements during the indoor feeding season.

It is thought that only around 20 to 30 percent of the vitamin B produced in the intestines is absorbed by the horse. However, most types of vitamin B are produced in sufficient quantity in the intestines. Despite this, race horses in particular may require supplementary vitamin B as it aids the energy production in muscles, the work of the nervous system and metabolism. Foals can often develop vitamin B deficiencies as their digestive system has not fully developed. The need for vitamin B is emphasized in all horses during illness, stress, digestive problems, receiving antibiotics, changes is coating and when aging. Poor quality hay and too much concentrate feed can also increase the need for vitamin B.

Vitamins are divided into water soluble ones (vitamin B, C) and fat soluble ones (A, D, E, K) depending on how they dissolve and are stored in the horse’s body. Fat soluble vitamins are stored in the fatty tissue, liver and kidneys, while water soluble vitamins aren’t stored at all but pass through the body and are discharged in the urine.

See Hoof´s vitamins here

Fat soluble vitamins A, D and E are recommended to provided daily during the indoor feeding season in the Nordics.

Vitamin A improves immunity, metabolism, eyesight, mucous membranes, skin condition and reproductive functions. Supplementary vitamin A should be provided to foals and pregnant mares especially. Vitamin requirements also increase slightly from strain, but greater deficiencies are rare as vitamin A stores well and goes a long way.

Vitamin D is obtained from sunlight so deficiencies in the Nordics occur especially during the dark periods. Vitamin D is an extremely important part of bone growth in foals. Deficiency prevents ossification and the skeleton may remain brittle, causing back pains amongst other issues. Extensive training of a horse also increases the need for vitamin D.

Symptoms of vitamin E deficiency are not visible, so its consumption must be monitored

Vitamin E is the most important vitamin as horses cannot store it very well. Vitamin E acts as a natural antioxidant supporting the immune system under strain. The vitamins main task is to protect the cells and their mediums from oxidation caused by free radicals, unstable chemical compounds. Active muscle cells are very susceptible to the damage done by free radicals, which is why foals, brood mares and race horses need more vitamin E than on average to maintain normal muscular and nervous functions and to prevent illnesses related to these.

Adding vitamin E to the horse’s diet is highly recommended during the indoor feeding season in the Nordics and also during summer if a horse does not receive fresh grass as its main feed.

See Hoof´s vitamin E supplements here

Vitamin K affects the clotting of blood and the forming of bones. This vitamin is especially required for foals and during illness and when receiving antibiotics. Vitamin K deficiencies are rare as it is formed naturally in a horse’s intestines through microbe activity.

A healthy and well-nourished horse produces vitamins B and C themselves

In addition to acting as an antioxidant, vitamin C helps with the absorption of iron. This vitamin also acts as a catalyst for producing collagen, that cartilage, tendons and connective tissue require for maintenance and development. Vitamin C also helps maintain the horse’s immunity and aids the healing process. Vitamin C impacts the well-being of a horse on a broad spectrum.

The horse produces the necessary vitamin C from glucose in the liver, but this production can be disrupted due to stress or illness. Vitamin C is poorly absorbed in the large intestine so a horse needs all the vitamin C it produces. Vitamins B and C are water soluble so excess vitamins are discharged through urine. This means possible excess consumption is not harmful.

See Hoof’s vitamin C supplements here

Vitamins B1 and B2 are extremely important in the metabolization of fats, proteins and carbohydrates

Vitamin B1, known as thiamine impacts the functioning of the enzyme system, which greatly affects a horse’s performance. It also impacts the nervous system and soothes horses suffering from stress. In normal conditions a horse’s own micro-organisms will produce enough vitamin B1 themselves. Race horses should receive supplements.

Vitamin B2, known as riboflavin aids the functioning of the enzyme system that handles carbohydrates, amino acids and fats. This vitamin has an important role in relation to growth and health and its strongly associated with energy production and eye sight. Foals are dependent on supplementary vitamins until their own bacteria starts producing vitamin B2.

Vitamin B3, known as niacin and nicotinic acid, partakes in different stages of the metabolism and energy production. It also impacts the health of the skin and eyesight. Symptoms of deficiency normally show up as lack of appetite and diarrhea. Niacin is only stored in the body for a day after which it disappears. Deficiency does not cause severe symptoms and usually a horse will not require vitamin B3 supplements if their diet is in order.


Vitamin B7 (vitamin H), known as biotin helps protein absorption and grows the hooves and improves their quality. This vitamin is also necessary for the growth of cells, production of fatty acids and the metabolism. Deficiency can cause tiredness, skin problems and a weak appetite. Biotin is formed in a horse’s intestines but this may be insufficient for a horse in active labour.

In conjunction with vitamin B12 and vitamin C, Folic acid takes part in the production of hemoglobin for red blood cells, which is especially important for horses under heavy strain. Folic acid also aids protein metabolization and is essential for the growth and renewal of tissue.

Vitamin B12 is the only vitamin B that doesn’t occur naturally in plants, so a horse must receive it either through their own bacteria or from complimentary feed. Red blood cells, certain amino acids and the hooves of horses need vitamin B12 as building blocks. Vitamin B12 also contains sulphur that foals needs in order to grow.

See all of Hoof’s vitamin B options here

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