Editor’s note: This article has been reprinted. First published November 21, 2016.
Pregnant women can optimize their child’s health by getting enough vitamin B12. A 2016 study found that babies of mothers who had B12 deficiency during pregnancy were more likely to develop type 2 diabetes and other serious metabolic problems later in life.1
If you’ve ever felt “tired” and had an overall lack of energy, you likely have a vitamin B12 deficiency. It hasn’t been discovered for many years. In fact, about 15% of the U.S. population suffers from this condition.
However, a number of seemingly unrelated symptoms, such as memory loss, shortness of breath, loss of taste and smell, depression, and tingling in the extremities, may indicate that it is a good idea to check your B12 levels.
Interestingly, Mary Todd Lincoln, the wife of President Abraham Lincoln, who was known to be emotionally and psychologically unbalanced, had these symptoms and several more that scientists theorized were the cause of her behavior. At the time, doctors called it pernicious anemia, a vitamin B-related disease.2
Vitamin B12 (aka cobalamin), which is found in animal foods such as eggs, milk, cheese, yogurt, meat, fish, and poultry, is also available in supplement form. It is called “essential” because the body cannot produce it. It must come from an external source.
Why do you need B12?
Vitamin B12 is essential for many functions throughout the body. It does the following:
adrenal hormone production | folic acid metabolism3 |
fat and carbohydrate metabolism | red blood cell synthesis |
iron absorption | proper blood circulation |
reproductive health | digestion |
nervous system function | Nerve growth and function |
How much vitamin B12 do you need?
National Institutes of Health (NIH)4 Daily recommendations for vitamin B12 supplementation include: The dosage is gradually increased as the child matures.
- 2.4 micrograms for those 14 years and older
- 2.6 micrograms for pregnant women
- 2.8 micrograms for breastfeeding women
But for many, it’s not enough. This one vitamin is at least partially responsible for producing DNA as well as red blood cells and nerves, says Harvard Health.5
“And therein lies the problem: Some people do not consume enough vitamin B12 to meet their needs, while others cannot absorb enough, no matter how much they consume. As a result, vitamin B12 deficiency can occur, especially in: It is relatively common in older people.”
According to The Washington Post, vitamin B12 is water-soluble, so you don’t have to worry about overdosing it. Therefore, “the body takes only what it needs and flushes out the rest”.6
B12 Deficiency — Vicious Cycle
Scientists already know that pregnant women with lower B12 levels have a higher body mass index (BMI), said Dr Ponnusamy Saravanan, clinical associate professor at Warwick Medical School in the UK and lead author of the study. And babies born with low birth weight.
Studies have shown that these babies have greater insulin resistance at an early age, which automatically sets them up for developing type 2 diabetes later in life.
The researchers wondered whether the symptoms seen in babies whose mothers had low B12 levels were actually related to leptin, the so-called “satiety hormone” that triggers the perception of when one is full.
Research shows that knowing when to stop eating is an important factor in maintaining a healthy weight. The problem arises when leptin levels increase in overweight individuals, masking feelings of fullness so they still feel hungry, leading to persistent overeating. This phenomenon is called leptin resistance.
It becomes a vicious cycle in which hunger cannot be satisfied even if you eat properly. Therefore, you slowly gain weight, become more and more leptin resistant, and eventually become more insulin resistant. At the same time, your risk of developing type 2 diabetes increases.
Additional findings from the study
Saravanan’s team analyzed 91 blood samples from mothers and newborns to test vitamin B12 levels. At the same time, they examined 83 samples of fat tissue and tissue from the placenta.
Of course, scientists have found that babies of mothers with vitamin B12 deficiency often have higher-than-normal leptin levels. Saravanan explained:7
“The nutritional environment a mother provides can permanently shape her baby’s health. We know that children born to undernourished or overnourished mothers are at increased risk for health problems such as type 2 diabetes, and “We know that B12 deficiency can also affect adiposity, which is why we decided to look at the fat cell hormone leptin.”
Scientists have hypothesized that if B12 is not adequately supplied to pregnant women, the hormone responsible for programming the baby’s leptin gene is affected. Researchers aren’t sure what mechanisms determine these results, but they have some ideas.
Adaikala Antonysunil, associate professor and researcher and co-author of the study, said vitamin B12 deficiency could cause the fetus to store fat and produce more leptin, or B12 deficiency could alter the mother’s gene that produces leptin.
It is probably the latter, as B12 is involved in methylation reactions that affect whether genes are activated or deactivated. If they are right, researchers believe that current U.S. recommendations for B12 levels for pregnant women should be increased.
Signs of Vitamin B12 Deficiency
About 3.6% of American adults have vitamin B12 deficiency.8 One of the hallmarks of deficiency is fatigue. Vitamin B12 plays an important role in energy production and metabolism. Vitamin B12 also contributes to anxiety and depression because it is a coenzyme in the synthesis of neurotransmitters that regulate mood. Without intervention, low B12 levels can also cause paranoia, delusions, and hallucinations. Other signs include:
Numbness and a tingling, “pins and needles” sensation in the hands, legs, or feet indicate possible nerve damage. | Yellow skin indicates that your red blood cells are deteriorating, releasing yellow pigment in the process. |
A swollen, “smooth” tongue with fewer “bumps” that contain taste buds. One patient recovered completely after receiving B12 treatment.9 | Feeling unsteady, shaking, and dizzy are signs that your blood is not getting enough oxygen related to low B12. |
Damage to the optic nerve from B12 deficiency can cause blurry, double vision, or shadows. | Amnesia is a red flag when there are no other possible causes. |
What Causes Vitamin B12 Deficiency?
There are several major reasons for B12 deficiency that doctors sometimes overlook. Individuals at risk for B12 deficiency include:
Vegetarians and vegans do not get B12 from animal foods. |
People who drink alcohol regularly because B12 is stored in the liver. |
People with an autoimmune disease, such as Crohn’s disease or celiac disease, that prevents the body from absorbing B12. |
People who drink more than 4 cups of coffee a day. Compared to non-coffee drinkers, the content of B vitamins, including B12, was found to be approximately 15% lower.10 |
People who have had gastric bypass surgery and have had their digestive system altered. |
People exposed to nitrous oxide, also called laughing gas, remove all B12 stores from their bodies. |
This is because the ability to produce endogenous factors decreases in older people as they age. Intrinsic factor is a protein produced by stomach cells that is required for B12 absorption. The H. pylori (Helicobacter pylori) bacteria also destroys it, preventing B12 absorption.11 |
People taking antacids, which may interfere with B12 absorption over time. |
Patients taking metformin for hypoglycemia may need to be treated for hypoglycemia because the drug interferes with B12 absorption. |
People taking proton pump inhibitors, such as Prevacid or Nexium, or H2 blockers, such as Pepcid or Zantac.12 |
Vitamin B12 exists in natural form only in animal sources. Vegans are encouraged to stock up on nutritional yeast, coconut oil, and fortified coconut milk to increase their B12 intake, but a strict vegan or vegetarian diet is not recommended. In fact, there are cases where deficiency causes brain abnormalities.
Deficiency is corrected by weekly vitamin B12 injections or daily high-dose B12 supplements; in mild cases, it is corrected by standard supplements or increasing the intake of vitamin B12-rich foods.13 A more detailed list of B12 in specific foods can be found at the NIH.14
