Why B12 is Crucial for a Healthy Pregnancy
by Ashleigh Feltham,  Accredited Practising Dietitian and Accredited Nutritionist.

Diet is one of the factors that contributes to a successful pregnancy. Including a range of the right foods provides your body with the energy it needs and essential nutrients for a healthy mother and baby. Vitamin B12 in particular is crucial for a successful pregnancy.

Vitamin B12, also called cobalamin, is one of eight B vitamins. B12, a water-soluble vitamin, is vital for keeping your nerve cells and red blood cells healthy. B12 also plays an important role in promoting tissue, eye and brain health. Natural vitamin B12 is predominantly found in animal food products.

B12 is also needed to make DNA, which stores your body’s genetic material. Being deficient in B12 can affect your memory and can be misdiagnosed with conditions such as dementia, especially in the elderly.

Research shows that suboptimal levels of vitamin B12 during pregnancy has negative effects on the health of the infant, both in the short and long term.

A literature review highlights the effects of vitamin B12 deficiency on pregnancy outcomes for both the mother and infant. It shows that B12 deficiency is associated with high blood levels of homocysteine concentrations at 18-20 weeks of gestation. Homocysteine is an amino acid found in your blood. High levels of this amino acid is linked to poor health outcomes and disease states. There is a correlation between these high homocysteine blood concentrations and damage to the DNA of the mother.

This DNA damage is associated with an increased risk of developing preeclampsia and intrauterine growth restriction. Preeclampsia precipitates symptoms of high blood pressure and abnormally high levels of protein in the urine, called proteinuria, in the twentieth week of pregnancy.

Another study investigated the effects of vitamin B12 deficiency on pregnancy outcomes. Researchers conclude that there is an association between vitamin B12 deficiency and an increased risk of developing megaloblastic anaemia, a type of anaemia that causes very large red blood cells.

Megaloblastic anaemia during pregnancy is linked to many ill health outcomes for the baby. These outcomes include an increased risk of low birth weight, permanently effecting the cognitive development of the foetus, an increased risk of neural tube defects, increased risk of re-occurring pregnancy losses, anaemia and intrauterine growth restrictions.

There is also a link between low concentrations of vitamin B12 in the blood and an increased risk of the infant developing insulin resistance as well as a higher likelihood of being born with a congenital heart defect.

This research reinforces the importance of including enough foods in your diet that are sources of vitamin B12. B12 is naturally found in animal foods, such as:

• Eggs, mostly in the yolk
• Dairy – cow’s milk, cheese, yoghurt
• Red meat – beef, lamb, game meats like kangaroo, pork
• White meat – all varieties of poultry
• Fish – all varieties, particularly tuna and haddock
• Shellfish – all varieties

Vitamin B12 can also be added to food or drinks through fortification, such as in soy milk, nutritional yeast, cereals and rice milk.

Take home message:

Vitamin B12 is essential for health throughout your life. This is true from the beginning of development in the womb, when the mother is the single source of nutrition for growth and development.

References:

1. Herbert V, Drivas G, Manusselis C, Mackler B, Eng J, Schwartz E. Are colon bacteria a major source of cobalamin analogues in human tissues? 24 hr human stool contains only about 5 ug of cobalamin but about 100 ug of apparent analogue (and 200 ug of folate) [letter]. Trans Assoc Am Physicians 1984;97:382.
2. Carmel R, Karnaze DS, Weiner JM. Neurologic abnormalities in cobalamin deficiency are associated with higher cobalamin ‘analogue’ values than are hematologic abnormalities. J Nutr 1995;125:2511–5.
3. Kondo H, Binder MJ, Kohhouse JF, Smyth WR, Podeil ER, Alien RH, et al. Presence and formation of cobalamin analogues in multivitamin-mineral pills. J Clin Invest 1982;70:889–98.
4. Health AGDo. Eat for Health Australia: Australian Government National Health and Medical Research Council; 2015 [cited 2017 27/02/2017].
5. Julia L Finkelstein, Alexander J Layden, Patrick J Stover, Vitamin B-12 and Perinatal Health, Advances in Nutrition, Volume 6, Issue 5, September 2015, Pages 552–563
6. Furness, D., Fenech, M., Dekker, G., Khong, T.Y., Roberts, C. and Hague, W. (2013), Folate, Vitamin B12, Vitamin B6 and homocysteine: impact on pregnancy outcome. Maternal & Child Nutrition, 9: 155-166.