Replacing all meat with refined grains may increase the risk of vitamin B12 deficiency more than simply eating less meat, because complete shifts to plant-based diets low in essential nutrients can...
Mechanism
Synthesis from 1 study
When people stop eating all meat and eat mostly white rice or bread instead, they stop getting vitamin B12 from food. The body uses up its stored supply over time and can't make enough healthy blood cells or keep nerves working right. If people still eat some meat, like fish or chicken, they get...
Most probable mechanism
When meat is completely removed from the diet and replaced with refined grains, the body gets almost no vitamin B12 from food. Without enough B12, the liver can't store what it needs, and the blood can't make healthy red blood cells or maintain nerve function properly.
Dietary intake of vitamin B12 falls below the physiological threshold required to maintain serum concentrations due to elimination of animal-derived food sources.
Low serum vitamin B12 levels reduce the availability of the cofactor for methionine synthase and methylmalonyl-CoA mutase, impairing cellular metabolism and red blood cell formation.
Hepatic vitamin B12 stores decline over time due to lack of replenishment, leading to systemic deficiency even if initial serum levels appear normal.
Evidence from Studies
Supporting (1)
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Substituting animal protein foods with plant protein foods influences vitamin B12 and folate statuses in a multiethnic Asian population
Contradicting (0)
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