Yellowish skin
A lesser-known but significant symptom of vitamin B12 deficiency is jaundice, or icteris. This manifests as a yellow or green discoloration of the skin and whites of the eyes. This symptom is caused by elevated levels of bilirubin, a breakdown product of red blood cells. When the production of healthy red blood cells is disrupted due to a B12 deficiency, bilirubin accumulates in the blood, giving the skin and eyes a yellowish tint. Typically, the skin appears pale with a yellowish hue.
Blurred vision
A severe vitamin B12 deficiency can also affect vision. This deficiency can damage the optic nerve, resulting in blurred vision. People may think they need glasses when the problem actually lies in a vitamin B12 deficiency. Before changing glasses, it is recommended to have vitamin B12 levels checked. Appropriate supplementation can help restore normal vision if a B12 deficiency is the underlying cause of the problem.
Muscle weakness
Muscle weakness is another notable symptom of vitamin B12 deficiency. This weakness is not always resolved by exercise alone, as it has a biochemical cause. Vitamin B12 is essential for the synthesis of red blood cells, which carry oxygen throughout the body, including to the muscles. When muscles do not receive enough oxygen due to a red blood cell deficiency, they can become weak and fatigued. This muscle weakness can affect daily activities and reduce quality of life. Taking vitamin B12 supplements can help improve muscle strength by increasing red blood cell production and improving oxygen delivery to the muscles.
