What Happens If A Horse Has Too Many Vitamins?

What Happens If A Horse Has Too Many Vitamins?

It’s a common misconception that you could give loads of vitamin or mineral supplements to a horse and whatever isn’t used by their bodies will go out in the form of waste. As a result, most people believe that over-supplementation isn’t detrimental to the health of their horses.

While horses need supplements such as vitamins, minerals, and probiotics, they only need these nutrients in safe and limited quantities. If you overload your horses with too many nutrients, this could have serious consequences on their health. In today’s blog post, we will explore how many vitamins are too much for a horse and what the side effects of over-supplementing your horse are.

What is Vitamin Toxicity?

Vitamins may be categorised on the basis of their solubilities such as fat-soluble vitamins and water-soluble vitamins. The good thing about water-soluble vitamins is that any excess is simply excreted by the body. If you excessively feed your horse with water-soluble vitamins, you will only be wasting money. On the other hand, excessive feeding of fat-soluble vitamins is a concern because these types of vitamins get stored and processed in the liver, leading to very concerning trouble.

Fat-soluble vitamins include vitamin A, vitamin D, vitamin E, and vitamin K. Here’s what you need to know about the ill effects of excessive dosage of these vitamins:

1). Vitamin A

Vitamin A has antioxidative properties. It is also known to be useful for boosting the immune system, reproductive functions, and vision of horses. Naturally, the intestine synthesises it from beta-carotene. Fresh forage has beta-carotene in abundance.

Vitamin A is fat-soluble which means it gets stored in the liver. Horses have evolved to store it in the liver as they can use it during the winter months due to the non-availability of fresh grass. Its requirement is estimated at 30 IU per kilogram of body weight for adult horses and maintenance and at 45 IU per kilogram of body weight for exercising and growing horses. For a 500 kg horse, the estimated upper limit is around 160,000 IU per day.

Over-supplementation of vitamin A can lead to abnormal bone growth, bone fragility, decreased blood clotting, scaly skin, and poor hair coat. Over-supplementation isn’t typically an issue but it’s important to note that almost everything is fortified with vitamin A as it is considered safe. Therefore, it is worth being cautious about how much vitamin A your horse is consuming.

What happens if horse too many vitamins

2). Vitamin D 

Vitamin D is essential for promoting the absorption of calcium and phosphorus. It is also believed to help with the mobilisation of stored calcium in the body which affects bone mineralisation.

Vitamin D toxicity in horses is a real risk. When it comes to supplementation, the recommended daily dosage for mature horses is  6.6 IU of vitamin D per kilogram of body weight. For growing horses, the recommended daily dosage varies with age ranging from 22.2 IU per kilogram of body weight to 13.7 IU.

Excessive supplementation of vitamin D can lead to weight loss, stiffness, low activity levels, high concentration of phosphorus in the blood, and lower feed intake.

3). Vitamin E 

There are extremely rare cases of vitamin E toxicity It is believed that it may affect the absorption of other fat-soluble vitamins in the body.

4). Vitamin K

Vitamin K is available in both water-soluble and fat-soluble forms. K3 is the most common commercially available form of vitamin K which happens to be water-soluble. It can be injected intravenously or intramuscularly but any mistake in the measurements may lead to acute renal failure and other health complications.

Final Thoughts

If you are cautious and mindful of your horse’s digestive intake, you won’t need to worry about vitamin over-supplementation. However, over-supplementation of vitamins it is a real risk and can have serious health consequences. This is why it’s important for you to be on the lookout for common symptoms of vitamin toxicity and take corrective measures in case you notice something is not normal.

Equine America NZ is the leading provider of high-quality supplements for horses. We have been serving customers for more than 20 years and all of our products are manufactured in the UK.

Please give us a call at Equine America NZ today at 0800 440 888 to learn more or leave an enquiry.