“That makes it look and feel kind of smooth and glossy. Infections, medication, and other conditions can cause it, too.
“But if not enough B12 or other nutrients is to blame, your tongue also may be sore.”
And Harvard Health cites a “swollen, inflamed” tongue as an “overlooked” symptom.
It says: “Vitamin B12 deficiency can be slow to develop, causing symptoms to appear gradually and intensify over time.
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