This last term is included to account for naturally occurring production and absorption of CSF.
Intake of dietary folate equivalents, which account for differences in the absorption of naturally occurring food folate and the more bio-available synthetic folic acid, was an important predictor of intake in general, even after adjusting for caloric intake.
Especially valuable are proton magnetic resonance spectroscopy, which measures the resonances due to energy absorption by hydrogen atoms in organic compounds, and carbon-13 magnetic resonance spectroscopy, which yields the resonances due to absorption by atoms of carbon-13 (13C), a naturally occurring isotope of carbon that contains six protons and seven neutrons.
Another complicating factor is that inorganic phosphate from preservatives may have much higher bioavailability, resulting in more than 90% absorption, compared with only 40 60% for naturally occurring dietary phosphate [ 20].
As a result, the naturally occurring mixture of gadolinium isotopes also has a very high nuclear absorption cross section on the order of 49,000 barns.
Xie has argued that the hiatus is the result of heat absorption by the Pacific Ocean -- a little-understood, naturally occurring process that repeats itself every few decades.
In contrast, the naturally occurring Zn in SFK that provided 90% of the rat's requirement was enough to deter excessive absorption of Cd and enough to alone prevent significant elevation of organ Cd.
Besides its contribution to nutrient absorption, passive, paracellular absorption has physiological and ecological importance as a pathway for absorption of appropriately-sized toxins made by humans (e.g., carbamate insecticides, glyphosate herbicide) and naturally occurring toxins in foods (e.g., caffeine, nicotine, some flavonoids).
Anglesite, naturally occurring lead sulfate (PbSO4).
Human-made ecocide and naturally occurring ecocide.
