A lot riders give extra vitamines and powders to the horse's food. It is no secret these vitamins are important for every horse. But does your horse need a specific type of supplement? And how much? Some horses might benefit from a vitamin supplement, but many are able to obtain the vitamins they need through their regular diets. The best first step one can make is to consult your veterinarian or equine nutritionist. Through a blood test they might determine what specific vitamine supplements are necessary four your four-legged friend. Vitamin supplementation might be beneficial for: Horses on a high-grain, low-forage diet (such as youngsters in heavy race training), or for those on very poor-quality forage or eating hay that is more than a year old. Vitamins tend to break down over time in stored feed. For example, there is a 9.5% loss of vitamin A activity in hay every month. Horses receiving prolonged antibiotic treatment for illness or infection. Broad-spectrum antibiotics inhibit the growth of the beneficial cecal and intestinal bacteria, which inhibit their production of B vitamins and vitamin K. Horses in high-stress situations, such as frequent traveling, showing, or racing. Horses who are eating poorly—for example, those recovering from surgery or illness. Horses who are anemic—although the source of the anemia should be determined and treated first. Vitamins in feed can decompose when exposed to sunlight, heat, air, or the processes that feed goes through in commercial packaging (such as grinding or cooking). Losses during long-term feed storage are greatest for vitamins A, D, K, and thiamin (B¹). Vitamin A is the most crucial of these because the horse does not manufacture it within his own system. Furthermore, some vitamins are incompatible with each other or with minerals that might also be in the feed. For example, most vitamins are prone to oxidative destruction by iron, copper, sulfates, sulfides, phosphates, and carbonates, all of which might be present in a feed or a vitamin/mineral supplement. The B vitamin thiamin (B¹) is incompatible with riboflavin (B²), and both are incompatible with cobalamin (B¹²) in the presence of light. So feed manufacturers might go to great lengths to protect the vitamins’ activity and efficacy by coating them with gelatin, wax, sugar, or ethylcellulose—harmless, fortunately, to the horse in the amounts required. These compounds might compose a large part of a powdered or pelleted vitamin/mineral supplement. (Interestingly, it’s very difficult to cover vitamins with any sort of protective coating in a liquid format, so many of the liquid supplements rich in B vitamins, iron, and copper, sold as “blood builders,” might actually have very little active vitamin content.)
