Signs & Symptoms of Vitamin B6 & B12 Deficiency

While severe vitamin B6 and B12 deficiency is rare in developed countries, many people may still be at risk for mild deficiency, particularly in vitamin B6. Since animal products are the richest sources of vitamin B12, vegans and strict vegetarians are at higher risk for low vitamin B12 levels. Certain medications and digestive tract surgeries as well as alcoholism can also lead to B vitamin deficiencies.

Consult a physician if you suspect that you have either a vitamin B6 or B12 deficiency.

Psychological Symptoms

Vitamin B6 is particularly important for brain function because it helps the body form certain neurotransmitters. Both vitamin B6 and vitamin B12 deficiency can interfere with mood and memory. A lack of these vitamins can cause depression, irritability and trouble concentrating. Memory impairment may range from short-term memory loss and confusion to dementia.

Skin and Mouth Problems

Because the B-complex vitamins help maintain skin health, not getting enough of them can lead to skin problems. If your diet lacks sufficient vitamin B6 or B12, you may develop sores in your mouth, and your tongue may become sore or inflamed. Sores or ulcers around the corners of the mouth are another sign, particularly of vitamin B6 deficiency. A lack of vitamin B6 may also cause dermatitis.

Neurological Symptoms

If you're seriously deficient in vitamin B12, your arms and legs may feel weak, numb or tingly. Muscle weakness is also a symptom of vitamin B6 deficiency and with severe vitamin B6 deficiency, convulsions are also possible. Additionally, low levels of vitamin B12 can lead to loss of balance.


Anemia is a lack of healthy red blood cells, the cells that carry oxygen to the body's tissues. This condition causes fatigue, shortness of breath and pale skin, among other symptoms. Because the body needs vitamin B12 to make red blood cells, insufficient levels of this vitamin can lead to anemia.