Back to Basics: Horse Nutrition – Part 2


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Back to Basics: Horse Nutrition – Part 2

Back to Basics: Horse Nutrition – Part 2

In Part 2 of "Back to Basics Horse Nutrition," we will now look at vitamins and minerals! Our new Spalding Series will give you an overview of which vitamins and minerals are vital to your horse's health, the science behind this and what happens to your horse if he is deficient in any specific area.  If you missed part one of our series you can catch up here 

Mares and foals often share feed bowls early on*


What are vitamins and minerals?

In addition to water, energy and protein, cells require certain levels of micronutrients to function properly. Vitamins and minerals help to regulate numerous functions within the body, from the immune system through to reproduction and energy release.  Vitamins are either fat soluble or water soluble, depending on how they are stored within the body. The major fat-soluble vitamins required by the horse are A, D and E while the water-soluble vitamins are referred to as B vitamins, including thiamin, riboflavin and biotin among others. Minerals are divided into two classifications: macrominerals and trace minerals. The horse requires a high intake of macrominerals - these include calcium, phosphorus, magnesium, potassium and sodium and are essential for regulation of the nervous system, skeletal development, muscle contractions and hair and hoof growth.  Trace minerals, sometimes referred to as microminerals, are required in much smaller quantities; they are vital for metabolism and nerve transmission, and include zinc, selenium, iron and copper.




Vitamins are important for every function in the body. As an overview, vitamins A, D and E – the fat-soluble vitamins – operate as antioxidants, protecting cell, nerve and muscle function. They are stored within body fat and, as quantities accumulate over time, if over-eaten they can lead to toxicity.  Water-soluble vitamins – B group and C – are not stored by the body and therefore must be supplemented through diet to meet the needs of the horse. They are critical for biochemical processes such as nerve transmission through to immune strength and growth. It is unlikely that a horse can be overfed these types of vitamin as they are excreted if unused. However, any deficiency can lead to health problems.

Here we have compiled a simple chart on each vitamin’s purpose and main sources of availability – why not print it out and keep it with your horse’s feed charts for easy reference?


Type of vitamin




Fat soluble


Vision, growth, tissue formation, reproduction

Herbs, vegetable-based oils


Bone structure

Sunlight, oils


Muscle structure, fertility

Grass and hay


Blood clotting

Grass and hay

Water soluble

B group

Digestion and absorption of food, nerve transmission and function

Hindgut digestion of grass and forage


Immune function, function of blood and blood vessels (along with iron)

Hindgut digestion of grass and forage



Minerals are nutrients that are required only in small amounts by the horse’s body but are essential nonetheless. Their main role is the development and upkeep of the skeleton and bone structure. They are present in the fluid content of cells and facilitate functioning of enzymes, nerve transmission, hormones and blood formation.  In the same way we looked at vitamins, here is a breakdown of the minerals required and their sources of origin:




Calcium and phosphorus

Bone structure – must be fed in a ratio of 2% calcium:1% phosphorus, calcium is also important in blood clotting

Good-quality hay, alfalfa (note: oats, barley and maize in straight forms contain too much phosphorous in relation to calcium, sugar beet pulp is the opposite); supplementation may be required.


Bone structure and nerve transmission

Good quality grass

Sodium , chlorine and potassium

Otherwise known as electrolytes, they  regulate fluid balance within the horse including heart function and excretion rates

Grass and hay; supplementation may be required


Production of enzymes, hormones and amino acids

Grass and hay; supplementation may be required


Involved in blood formation and transport of oxygen

Found in grass in the small amounts required although certain soils may be deficient and thus the horse may require an iron supplement in his diet


Reproduction and hormones

Found in grass in the small amounts required although certain soils may be deficient and thus the horse may require a zinc supplement in his diet


Works with vitamin E in muscle use

Found in grass in the small amounts required although certain soils may be deficient and thus the horse may require a selenium supplement in his diet


This basic overview gives you a solid understanding of the building blocks of nutrition, the reasons why we feed the horse certain nutrients and the risks of a diet that is unbalanced.  Without any of these fundamental nutrients the horse will not be able to function and his nutritional requirements will not be met. Horses that are suffering from any form of illness or recovery, or that are in the transitional life stage such as growth, pregnancy or old age, will need adaptations to these basic guidelines. Speak to your veterinarian or feed manufacturer for further advice.

To find out more about the nutrition for your horse keep visiting us here at

*Image courtesy of A Daff

  • I'm going to print this article out, It is just such as useful read - keep them coming, I am addicted to your blog Morgan