Vitamin B-6 and vitamin B-12 are key members of the B vitamin family, but they are not identical in their benefits to the body or the way the body processes them. While they are often taken in combination in the form of B-complex supplements, they can be taken independently and have different natural sources. The differences between them are important to understand to use them optimally to potentially boost your health.
Storage in the Body
The body stores B-6 and B-12 in the liver, but deficiency in B-12 is more common, according to the Linus Pauling Institute. A B-12 deficiency can result because the body has difficulty absorbing B-12 from the diet especially as it ages, making deficiency more common in older Americans who have exhausted their existing vitamin stores without being able to replenish them.
Vitamin B-12 has a singular structure shared by no other vitamin, notes the Linus Pauling Institute. It contains the rare element cobalt, making it the only vitamin to have a metal ion in its system. In contrast, the three most common forms of vitamin B-6 are based on pyridoxine, pyridoxal, and pyridoxamine. Both vitamins are water soluble and metabolize in the liver.
Vitamin B-6 and B-12 play different roles in mental health. Vitamin B-6 is essential for neurotransmitter synthesis, and impacts the brain's levels of the mood- controlling neurotransmitters serotonin and dopamine, according to the Office of Dietary Supplements. On the other hand, vitamin B-12 is related to memory, with low levels of B-12 associated with both dementia and Alzheimer's disease. Supplementation of B-12 for individuals with dementia has shown promise in reducing symptoms, though the supplement is not a cure, the Linus Pauling Institute reports.
Danger to the Body
Vitamin B-12 and vitamin B-6 pose different risk factors for the body. Vitamin B-6 is designed to be taken in doses of 1.3 mg per day throughout the majority of life, with an upper limit of 100 mg per day. Exceeding this upper limit can result in nerve damage, particularly in the arms and legs, notes the Office of Dietary Supplements. The damage is reversible if vitamin B-6 levels are lowered. On the other hand, the Linus Pauling Institute notes that vitamin B-12 has no upper limit in place and taking high doses cause no known side effects unless there is a pre-existing B-12 sensitivity.