1. What is bioavailability as it relates to vitamins? Do any factors affect the bioavailability of vi?

Answer 1

Bioavailability is the technical term used to convey the fact that you do not absorb 100% of all nutrients consumed, no matter if you take them in the form of nutritional supplements or as food.

The term 'bioavailability' attempts to include in a single concept the effect of a sequence of metabolic events, i.e., digestibility, solubilization, absorption, organ uptake and release, enzymatic transformation, secretion and excretion.

Various nutrients and dietary components interfere with the bioavailability of vitamins. Hence, requirements for vitamins cannot be considered independently, but must be evaluated in relationship to other nutrients and compounds consumed by an individual.

Answer 2

The bioavailability of vitamins
found in foods is 100% unless
the person has a digestive
problem.
the availability of vitamins
in supplement form is much
less. Depending on the
purity of the supplement, I'm
guessing not more than 60%.

Answer 3

Hi Tom. Bioavailability refers to the entire process of digesting, absorbing and utilizing a substance, including vitamins and other nutrients.

Many vitamins in food are attached to other molecules (e.g. proteins, amino acids, etc.) and require effective digestion to release the vitamins for absorption. B12 and folic acid are good examples.

Acid inhibiting drugs (e.g. Prilosec or Nexium - the little purple pill!) can lead to vitamin B12 deficiency because the lack of acid impairs digestion.

The four fat soluble vitamins (A, D, E, and K) require an adequate amount of fat in the meal to stimulate proper fat digestion (bile from the gallbladder and pancreatic enzymes). Without enough fat in the meal, or with poor fat digestion (e.g. gallbladder dysfunction) malabsorption of these vitamins is likely.

Hope you find this helpful. Best wishes.