Vitamin B12 and its Interactions
Our metabolism is a complex system of successive constructive and complementary reactions – no nutrient works alone for itself, on the contrary they are all dependent on interactions with numerous other nutrients. The same is true of vitamin B12.
Whilst numerous diseases and medications can negatively impact upon the effectiveness of vitamin B12, there are particular nutrients which can support its effect or even make it possible in the first instance. This article is designed to give an overview of these interactions and options for sensible nutrient combinations for vitamin B12 treatment, as well as for general health.
Vitamin B12 and Folic Acid
As the article vitamin B12 and folic acid explores in more detail, folic acid is the closest direct ‘partner’ of vitamin B12. Vitamin B12 is responsible for converting folic acid back into its bioactive form after various reactions – in other words, it reactivates it. Without vitamin B12, the body quickly suffers a functional folic acid deficiency, since the folic acid is left stuck inside our body in its unusable form. There is clearly enough folic acid present, but it cannot be converted.
On the flip side, vitamin B12 also requires folic acid: in the corresponding reaction, the folic acid (more specifically methyltetrahydrofolate) gives off a methyl group for vitamin B12, which reacts later. The methylcobalamin later passes on the methyl group to homocysteine, whereby it is converted into methionine.
Vitamin B12 and folic acid are directly dependent on one another in this reaction, because the reaction can only take place if both reactive partners are present. Folic acid deficiency is among the most common vitamin deficiencies in people.
Biotin (Vitamin B7)
The second bioactive form of vitamin B12, adenosylcobalamin, requires biotin (also known as vitamin B7 or vitamin H) and magnesium, in order to fulfill its important role in aiding the function of the engine room of our cells, otherwise known as the mitochondria. In this case, however, the dependency is indirect.
Adenosylcobalamin is part of the enzyme methylmalonyl-CoA mutase, which is involved in the conversion of methylmalonyl-CoA to succinyl-CoA. Methylmalonyl-CoA, in turn, is formed from propionyl-CoA in a previous conversion step, a step which is necessary for biotin and magnesium.1
In cases of a biotin deficiency, the situation can arise that there is clearly enough adenosylcobalamin available, but that it is useless because its reaction partners cannot be formed. In these cases, the symptoms of a vitamin B12 deficiency can occur, even though the B12 blood level remains normal. An MMA urine test, on the other hand, would show a vitamin B12 deficiency even though there actually isn’t one present. Taking vitamin B12 also wouldn’t bring an end to the corresponding symptoms, since the vitamin B12 simply remains ineffective due to the biotin deficiency.
Biotin reacts very sensitively to free radicals, so taking additional biotin becomes very necessary in cases of stress, high-performance sport and disease, during which the body’s biotin requirement increases enormously.
The absorption of vitamin B12 in the intestine via the intrinsic factor is a process dependent on calcium. In cases of a calcium deficiency, this absorption method becomes extremely restricted, which can lead to a slight vitamin B12 deficiency.
An example of this is when taking the diabetes medicine metformin, which lowers the calcium level in the intestine to such an extent that many patients develop a B12 deficiency. As studies were able to show, however, this can be offset by a simultaneous administration of vitamin B12 and calcium.2
As a result of poor eating habits, many people today suffer from over-acidification. This means that the majority of a person’s calcium intake is used to neutralize this acid. A severely over-acidified intestine can thus also lead to B12 absorption problems. This furthers the recommendation for a generally well-balanced basic diet.
A vitamin D deficiency can also lead to a calcium deficiency, even if the body tries to account for low calcium levels by mobilizing missing calcium from the bones. It can be particularly critical if a vitamin D deficiency coincides with over-acidification. In this case as well as in other situations, it can be sensible to take vitamin B12 supplements with calcium, in order to optimize the absorption rate of the intrinsic factor. Here, the organic calcium salts (calcium citrate, calcium gluconate and calcium lactate) are preferable to the poorly absorbed calcium carbonate.
Vitamin B12 Conversion By Vitamin B2 and B3
A further interaction concerns the conversion of vitamin B12 into its bioactive coenzyme form: the body can only use the B12 types methylcobalamin and adenosylcobalamin directly, whilst all other forms of vitamin B12 must first be converted by the body.
The conversion steps involved in this are dependent on the B vitamins vitamin B2 (riboflavin) and B3 niacin).3 In cases of treatment via high doses of cyanocobalamin or hydroxocobalamin, it can therefore be useful to take these vitamins as well as supplements, or ensure they are adequately provided through the diet.
Vitamin B12 Combinations
This article highlights just how sensitive and interwoven the biochemical balance of the body is. A healthy, basic diet, rich in raw foods will prevent most nutritional deficiencies occurring. Stress, disease and environmental toxins can lead to a diversity of deficiencies.
If vitamin B12 treatment is not giving the desired results, it could well be as a result of one of the interactions listed here.
In all cases, a combination of supplements can be a sensible way to ensure the whole B12 active complex is covered and thus ensure an optimal absorption and utilization of these key vitamins.
1 E.R. Stadtman, P. Overath, H. Eggerer, F. Lynen, The role of biotin and vitamin B12 coenzyme in propionate metabolism, Biochemical and Biophysical Research Communications, Volume 2, Issue 1, January 1960, Pages 1-7, ISSN 0006-291X, http://dx.doi.org/10.1016/0006-291X(60)90252-7.
2 Bauman WA, Shaw S, Jayatilleke E, Spungen AM, Herbert V. Increased intake of calcium reverses vitamin B12 malabsorption induced by metformin. Diabetes Care. 2000 Sep;23(9):1227-31. PubMed PMID: 10977010.
3 Pezacka E, Green R, Jacobsen DW. Glutathionylcobalamin as an intermediate in the formation of cobalamin coenzymes. Biochem Biophys Res Commun. 1990 Jun 15;169(2):443-50. PubMed PMID: 2357215.