Those with a deficiency, however, may struggle to notice changes in odour because low B12 levels can cause olfactory dysfunction characterised by a partial or complete loss of smell.
Other symptoms of B12 deficiency
B12 binds to the protein in foods and is unbound in the stomach with the help of hydrochloric acid and enzymes.
“From there, vitamin B12 combines with a protein called intrinsic factor so that it can be absorbed further down in the small intestine,” explains Harvard Health.
A deficiency in vitamin B12 can manifest in numerous ways, but fatigue, lightheadedness, and pale skin may be among the most apparent signs.