Vitamin B12 is largest and most structurally complex essential vitamin. Although no fungi, plant or animal (including humans) are capable of producing it, it is involved in the metabolism of every cell in the human body - the enzymes needed for its synthesis are only found in bacteria and archaea. Adding to its already complicated chemistry; it is only absorbed into the body in combination with a glycoprotein secreted in the stomach called gastric intrinsic factor (GIF). It is also known as cobalamin, named for the cobalt atom that is found at the centre of its chemical structure.
There are several different forms of cobalamin with varying degrees of bioavailability. Hydroxocobalamin is the main type found in foods and easily converts to methylcobalamin in the body. Methylcobalamin is the most bioavailable form of B12 and is readily absorbed from food. It requires very little modification into the active form of the vitamin in the body, saving metabolic energy and cellular resources. This form of B-12 can even cross the blood-brain barrier without assistance.
There are foods and supplements that contain a vitamin B-12 analog, which is inactive in humans. Most of the edible algae that claim to contain Vitamin B12 contain a form of B-12 called cyanocobalamin, which is the target of controversy in nutritional science. This is because the molecules responsible for transporting vitamin B12 in the body bond to B12 analogs including variants of cyanocobalamin, which have been shown to inhibit the body from absorbing bioactive B12. The only naturally occurring plant source of vitamin B12 ever shown to produce a positive effect on B12 levels is chlorella pyrenoidosa, which is known to contain significant amounts of methylcobalamin. This is the strain of chlorella we use exclusively in the formulation of Vytogo.