In bovenstaand artikel staat deze passage:
Efficiency Is the Other Reason Deficiency Is Rare
The human body has evolved with highly efficient and unique mechanisms to absorb, utilize, and conserve this vitamin. Our daily requirement is less than 3 micrograms a day—one microgram is one-millionth of a gram (1/1,000,000 gram).9 Which means, by design, people are expected to be exposed to only miniscule amounts of this essential nutrient.
Vitamin B12 is the only nutrient that requires a cofactor for efficient absorption. The cells of the stomach produce a substance, called intrinsic factor, which combines—after the acidic digestion of the food in the stomach—with the B12 released from food. This “intrinsic factor-B12 complex” then travels to the end of the small intestine (the ileum) where it is actively absorbed.
There is a second, much less efficient process, called “the passive absorption of B12” which also occurs in the intestine. This mechanism does not use intrinsic factor and as a result it is 1/1000 as efficient. But by consuming very large doses of oral B12, passive absorption will correct B12 deficiency even for patients with diseases of the stomach and small intestine.
On average, for someone raised on the Western diet, about 2 to 5 milligrams of B12 are stored, mostly in the liver. This means most people have at least a three year reserve of this vital nutrient. Conservation of B12 by the body boosts the time this supply lasts by 10-fold. After excretion through the bile into the intestines most of the B12 is reabsorbed by the ileum for future use. As a result of this recirculation it actually takes, on average, 20 to 30 years to become deficient after becoming a strict vegan. That is if no vitamin B12 were consumed—which is impossible, even on a strict vegan diet, because of bacterial sources of B12 from the person’s bowel, contaminated vegetable foods, and the environment.
Met andere woorden; een tekort is uiterst zeldzaam en vrijwel onmogelijk gezien de circulatie van B12 in het menselijk lichaam. Je gaat je toch afvragen wat er waar is en wat niet aan het hele B12 verhaal. Voorlopig blijf ik het nog wel gebruiken, want ik heb nog een aantal potjes staan, maar ik ga toch twijfelen als ik zoiets lees. McDougall is ook niet de eerste de beste natuurlijk.
Ook schrijft hij dit:
Efforts to lower homocysteine with supplements of folic acid and/or B12 have produced no reduction in heart disease or stroke12—and in fact the use of folic acid supplements increases the risk of cancer, heart disease, and overall death.13
Lees
hier het artikel over folic acid.
Folic Acid zit ook in Veg1...