B12 is one of the most powerful multifunctional vitamins for humans. B12's properties include tremendous effects on brain health and psychological function, on blood production processes, and on energy metabolism. It is unfortunate that such a necessary vitamin is found only in a narrow group of foods. People who follow a plant-based diet for ideological reasons or culinary preferences do not provide adequate amounts of vitamin B12 and have a high risk of deficiency.

In the diet, vitamin B12 is obtained from zoonotic products. This makes a vegan diet a strong indication for its supplementation. After switching to a plant-based diet, B12 deficiency is not immediately felt, because this vitamin is stored in the liver for a very long time, and a solid supply can protect against deficiency symptoms for many months. After that time, symptoms appear unexpectedly and are hard to link to a factor, so it is best to supplement it from the beginning to avoid such surprises.

However, a vegan diet is not the only indication for vitamin B12 supplementation. Let's check out who else should supplement it and what vitamin B12 is for.

• High homocysteine, cardiac issues and anemia
• Old age as an indication for B12 supplementation
• Vitamin B12 stores are depleted by some drugs
• B12 supplementation in mood disorders
• Who should watch out for vitamin B12 supplementation? Check the contraindications

High homocysteine, cardiac issues and anemia

Cardiovascular issues are a topic strongly associated with vitamin B12 supply, among others. Anemia caused by B-vitamin deficiency is a frequently diagnosed ailment for which B12 supplementation is recommended, accompanied by B6 and B9.

High homocysteine increases the risk of vascular inflammation and atherosclerosis. Its blood level is an important marker of cardiovascular disease risk. It is also a functional marker of saturation with the B vitamins B6, B9 and just B12. When homocysteine is too high, it is standard to include B12 supplementation along with B6 and B9. When there is a need for a more precise determination of vitamin B12 saturation, more advanced markers are tested in addition to homocysteine and blood B12 concentration: methylmalonic acid and holotranscobalamin. Abnormal results of these markers are an indication for additional supplementation.

Old age as an indication for B12 supplementation

The risk of neurodegeneration and other nervous system diseases increases significantly with age. Statistically, the frequency of use of B12-depleting medications also increases, and stomach acidity decreases, which significantly reduces the bioavailability of vitamin B12 from food. This makes many preventive supplementation protocols for seniors based on vitamin B12, among other things.

Vitamin B12 stores are depleted by some drugs

This fact is particularly well-known in relation to metformin, a very popular drug for hyperglycemia, used mainly for diabetes, insulin resistance and PCOS. If metformin is used long-term, it's worth consulting your doctor about the appropriateness of vitamin B12 supplementation to reduce the risk of anemia and neuropathy.

Nitric oxide, commonly known as "laughing gas," is also known to deplete B12 stores. It is used in anesthesiology as a gaseous anesthetic during medical procedures, and sometimes used recreationally.

B12 supplementation in mood disorders

Vitamin B12 affects both the overall health of the nervous system and specifically the metabolism of neurotransmitters that regulate our mood and emotional state. In order to reduce the risk of mood disorders or get rid of already present, mild symptoms, B12 is usually supplemented together with the entire B-Complex. For this purpose, B-Complexes with the active forms of the vitamins methylated B12 and B9, and vitamin B6 in P5P form, are usually recommended.

Who should watch out for vitamin B12 supplementation? Check the contraindications

With vitamin B12 supplementationyou need to be careful... with acne. While this is a surprising connection for many people, it has an excellent explanation in physiology and confirmation in research. In people with susceptibility to vitamin B12 supplementation (especially large doses), it can exacerbate the problem of acne, and in extreme cases even cause it. This effect is due to the fact that skin bacteria (associated with acne) produce vitamin B12. When this is administered in large amounts from the outside, the bacteria no longer need to produce it, but instead produce pro-inflammatory factors that cause skin lesions in greater amounts.

Sources:

• O'Leary F, Samman S. Vitamin B12 in health and disease. Nutrients. 2010 Mar;2(3):299-316.
• Yuan S, Mason AM, Carter P, Burgess S, Larsson SC. Homocysteine, B vitamins, and cardiovascular disease: a Mendelian randomization study. BMC Med. 2021 Apr 23;19(1):97.
• Aroda VR, Edelstein SL, Goldberg RB, Knowler WC, Marcovina SM, Orchard TJ, Bray GA, Schade DS, Temprosa MG, White NH, Crandall JP; Diabetes Prevention Program Research Group. Long-term Metformin Use and Vitamin B12 Deficiency in the Diabetes Prevention Program Outcomes Study. J Clin Endocrinol Metab. 2016 Apr;101(4):1754-61.
• Campdesuner V, Teklie Y, Alkayali T, Pierce D, George J. Nitrous Oxide-Induced Vitamin B12 Deficiency Resulting in Myelopathy. Cureus. 2020 Jul 9;12(7):e9088.
• Kang D, Shi B, Erfe MC, Craft N, Li H. Vitamin B12 modulates the transcriptome of the skin microbiota in acne pathogenesis. Sci Transl Med. 2015 Jun 24;7(293):293ra103.