Digestion Series: Part 8 - Transportation of nutrients

How do #nutrients that get absorbed from our small intestine get transported throughout our body?

It typically occurs in one of two ways: either via our circulatory system (#bloodstream) or our lymphatic system (lymph).

A majority of water-soluble nutrients like amino acids, electrolytes and water soluble #vitamins are transported primarily by our circulatory system. These nutrients enter the capillaries (the body's smallest blood vessels) which then feed into what's called the portal vein, which is the primary #blood vessel that carries blood from the intestines, gallbladder, spleen, and pancreas to the liver.

Fat (lipid)-soluble nutrients such as vitamins A, E, D and K are transported by the #lymphatic system. One key difference between nutrients transported by lymphatic system is that they enter the blood stream just before the heart, whereas substances carried by the portal vein first pass through the #liver where they can be metabolized (changed).

Why is this distinction between the circulatory and lymphatic system important? It is especially important when considering how quickly and in what form nutrients are present in to fuel the body. Since blood flow is significantly higher than lymphatic flow, nutrients that are #water soluble will circulate faster but also have the potential to be altered (metabolized) by the liver. #Fat soluble nutrients undergo less potential change but may take longer to reach their intended targets because of the slower lymphatic flow.

What does any of this matter? You often hear the term "bioavailability". Ingredient suppliers like to promote that their ingredient has, for example, "higher #bioavailability than competitor X". This claim often infers that the body is able to more efficiently absorb, process and deliver their #ingredient formulation versus a different form of the same nutrient.