By Sara Perkins, DVM

When choosing a supplement most of us study the label to check out the ingredients. Whether we are simply trying to provide daily requirements or attempting to improve a health issue, we look to see that the nutrients of interest are there and we might also be interested in the amounts. Unfortunately, the most important factor is not indicated on the label.

BIOAVAILABILITY is what it is all about. If an ingredient is listed on a label, it does not guarantee that it will be absorbed by the horse through the gut and go into the bloodstream to have an effect on the body. Consumers are largely on their own when it comes to sorting this out and deciding which products to trust. Frankly, it is a fairly complicated subject as many factors can determine how well a nutrient in a supplement is absorbed. To name a few:

• The exact chemical form of the ingredient (nutrients often come in various forms, some more easily absorbed than others)
• Ingredient quality
• Balance of ingredients (nutrients interact and can block or encourage the absorption of other nutrients, the recipe must account for these factors)
• Method of processing (some nutrients can be damaged, chemically altered, or lost when processing involves things like heat, pressing, or oxygen exposure)
• Final form of product (for example, some nutrients are better provided in a liquid form than a solid)
• Enhancers (some products contain yeast which assists the digestion of some nutrients)
• Absorption capacity of each nutrient (some are innately more easily taken in by horses than others)
• pH

Therefore, we must carefully determine how much of what is on the label actually gets to our horses. It is not spelled out for us. It is a matter of quality, care, integrity, and scientific development.