Essential Vitamins and Minerals
Professor Jo-Anne Murray
PhD, MSc, PgDip, BSc (Hons), BHSII, RNutr, PFHEA University of Glasgow Veterinary School
Vitamins and minerals are two of the six essential nutrients required by horses. Horses only need relatively small quantities of vitamins and minerals; however, an imbalance of these can be detrimental to your horse’s health and performance. The foundation of good nutrition is a balanced diet that ensures your horse receives all of the essential nutrients needed on a daily basis. Providing adequate vitamins and minerals in your horse’s diet is not an added bonus, but rather an absolute must as they are essential for your horse’s health.
Unfortunately, vitamin and mineral supplements are the most undervalued and underused supplement. You may not see the difference of feeding a vitamin and mineral supplement straight away, but your horse will feel the benefit. Moreover, your horse’s long-term health and performance may suffer as a result of you not providing adequate vitamins and minerals in his/her diet.
Minerals are inorganic nutrients required in relatively small quantities by the horse. Minerals are classified as either: macro (or major) minerals, and micro minerals (or trace elements). Macro minerals are those that are required and typically found in concentrations in the diet measured as grams per kilogram (g/kg), whilst micro minerals are required and typically measured in milligrams per kilogram (mg/kg).
Table 1: essential macro and micro minerals
Macro mineral requirements
The mineral requirements of a horse vary depending on bodyweight, age, physiological condition (e.g. pregnancy and lactation) and activity level (e.g. how much work the horse is doing). For example, mares that are in the late stages of pregnancy or are lactating, and young horses that are growing will have a higher requirement for some specific minerals (e.g. calcium and phosphorus) than other horses do. Most concentrate feeds have consistent mineral contents and can be estimated from nutrient tables; however, minerals in forages can vary significantly due to soil mineral content, plant species, stage of maturity of the forage at