Can be as simple as a B12 deficiency, too, which is ridiculously common. http://www.health.harvard.edu/blog/vitamin-b12-deficiency-can-be-sneaky-harmful-2013011

Can be as simple as a B12 deficiency, too, which is ridiculously common. http://www.health.harvard.edu/blog/vitamin-b12-deficiency-can-be-sneaky-harmful-201301105780 http://www.health.harvard.edu/blog/vitamin-b12-deficiency-ca...