Cobalamin Vitamin B12 & Folic Acid Deficiency in Spina Bifida / Neural Tube Defects

Biochemical assessment of Cobalamin Vitamin B12 & folic acid Vitamin B9 and its role in spina bifida

For many years cobalamin level has been tested by measuring its concentration in the serum. The normal value of cobalamin in blood serum is equal to or < 300 pg/ml. Its low concentration in serum is a sensitive indicator of probable neural tube defects, especially Spina Bifida [1]. With some minor changes in chemical composition of Vitamin B12 cobalamin is divided into three types:

  1. Cynocobalamin
  2. Hydroxycobalamin
  3. Adenosylcobalamin

However, it is important to note that the deficiency of any type of cobalamin and folic acid that can cause Spina Bifida and the other neural tube defects.

spina bifida b12 deficiency, spina bifida vitamin b12, spina bifida cobalamin

Source: ADAM Encyclopedia

When and how cobalamin Vitamin B12 and Vitamin B9 folic acid deficiency causes spina bifida

Neural tube defects occur in about 1 in 1000 births in USA and the most common known defect is called Spina Bifida. Therefore, women with low cobalamin levels are at a high risk of having a child born with SB.  Folic Acid Vitamin B9 or Cobalamin / Vitamin B12 given during the first 4 to 5 weeks of pregnancy can reduce the chances of Spina Bifida [2] by over 50%. Pregnant woman need a high quantity of cobalamin for fetal growth and development.  The stress of rapidly growing cells (fetus) requires a high amount of cobalamin. Therefore, its deficiency may increase during the gestation and can cause SB in child.

Low cobalamin or Vitamin B12 has been reported as a risk factor for neural tube defects as it acts as a co-factor for methionin synthase in the folate cycle. When cobalamin concentration is low, the folate needed for DNA synthesis remains stuck in the methylation cycle leading to impaired cell replication. Methionin synthase is necessary for the production of purines and pyrimidines. The reaction for the production of purines and pyrimidines occurs in the presence of methyl cobalamin where the methyl group of methyletetrahydrofolate is shifted to homocystien to produce methionin and tetrahydrofolate. Thus, the deficiency of cobalamin and folic acid and any interruption in the process of its synthesis leads to the development of neural tube defects like Spina Bifida.

Genetic role of Vitamin B12 cobalamin in spina bifida

People at risk of SB may have genetic variations/gene mutations that alter the metabolism of cobalamin. Any change in the  MTHFR gene or decreased concentration of cobalamin in relation with polymorphism in methionine synthase reductase (the enzyme that starts cobalamin methionine synthase) has been reported to increase the risk of Spina Bifida more than 5 times [3].

How to combate deficiency of cobalamin and folic acid to reduce the risk of spina bifida

Bioavailability

Cobalamin is produced by certain bacteria in the GI tract of animals and other mammals where it is absorbed by the host. Cobalamin is obtained only from animal sources [4] such as liver, eggs and dairy products. A small quantity of cobalamin is found in some seaweeds and mushrooms, but it is not active in the human body [5].

Some foods that are fermented by bacteria have been reported as containing cobalamin. Chances of the occurrence of SB depend upon the absorption of the bio-available sources in the gastrointestinal tract. Women with advanced age and those who have GIT problems are at high risk of producing offspring with SB.

Great video showing foods with a high amount of Vitamin B12

 

Synthetic availability

Adequate daily dietary intake of Vitamin B12 cobalamin or folic acid (vitamin b9) is recommended to minimize the chances of Spina Bifida. People with gastritis or above the age of 51 years can fulfill their daily dietary intake by synthetic cobalamin available in the form of food supplements or medication (tablets and injections).

How to avoid chances of spina bifida

Risk factors and chances of Spina Bifida can be reduced by regular monitoring and investigations. The following lab diagnostic tests are available for cobalamin values in the serum:

  • B12 can be measured in blood serum.
  • Complete blood count (CBC) is ordered daily for blood cell abnormalities, cell types, shape of cells and the quantity. The hemoglobin (HB) and red blood cell count may be low; shape of red blood cells may be altered (macrocytic). WBCs and platelet count may also be decreased.
  • Methylmalonic acid (MMA) is ordered after 3 or 4 days to detect the cobalamin deficiency.
  • Homocysteine is found elevated in cobalamin deficiency.

Video from the Spina Bifida Association about why you should take Folic Acid Vitamin B9

 

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References

  1. Food and Nutrition Board, authors; National Research Council, editor. Dietary reference intakes for thiamin, riboflavin, niacin, vitamin B6, folate, vitamin B12, pantothenic acid, biotin and choline. National Academy Press; Washington, DC, USA: 1998. Institute of Medicine, Vitamin B12; pp. 306-56.
  2. Anonymous. Recommendations for the use of folic acid to reduce the number of cases of spina bifida and other neural tube defects. MMWR Morb. Mortal. Wkly. Rep. 41 (Rr-14): 1-7, 1992.
  3. Wilson A, Platt R, Wu Q, Leclerc D, Christensen B, Yang H, et al. A common variant in methionine synthase reductase combined with low cobalamin (vitamin B12) increases risk for spina bifida. Mol Genet Metab. 1999;67:317-23.
  4. Stabler S.P., Allen R.H. Vitamin B12 deficiency as a worldwide problem. Annu. Rev. Nutr. 2004;24:299–326.
  5. National Health and Medical Research Council, authors; Department of Health and Ageing, editor. Australian Government; Canberra, Australia: 2005. Nutrient Reference Values for Australia and New Zealand; pp. 91-6.

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