Vitamin B12 Deficiency and Supplements, Surprising Information
Vitamin B12 deficiency is often cited as being a nutritional challenge for certain people, including vegetarians and the elderly as well as those with some gastrointestinal disorders. If you want to know how to avoid a B12 deficiency, the results of a new study can provide some answers, although you may be surprised to know it’s not as simple as just taking a supplement.
Do you get enough vitamin B12?
The recommended intake of vitamin B12 depends on your age and gender. For children ages 9 to 13, the recommendation is 1.8 micrograms (mcg); for individuals ages 14 and older, it is 2.4 mcg. Pregnant women need 2.6 mcg, while those who are breastfeeding should get 2.8 mcg daily.
Vitamin B12 is found primarily in animal based foods, such as meat, fish, shellfish, eggs, and dairy products. One exception is certain bacteria, which can produce vitamin B12 in the digestive tracts of animals. Supplements are another source.
But according to the results of a new study published in Journal of Agricultural and Food Chemistry, people may not be getting the vitamin B12 they have been led to believe from these and other foods, and not even from supplements.
In the current study, Fumio Watanabe and colleagues reviewed nearly 100 studies on vitamin B12, and here’s an overview of what they found.
- Some sources of vitamin B12 that come from the blue-green algae known as spirulina (a popular supplement available as a powder, tablet, and liquid) contain a pseudo form of vitamin B12 that the human body cannot utilize
- In addition, some forms of shellfish also contain the pseudo type of vitamin B12, such as abalone and whelks. However, more common shellfish such as mussels and oysters were found to contain the active form of the vitamin
- Multivitamin/mineral supplements that contain B12 may not provide consumers with the nutrient if the product also contains vitamin C and copper, as this latter combination can significantly destroy B12.
- Cooking can partially degrade the potency of foods that contain vitamin B12. Research shows that microwaving of beef, pork, and milk, for example, destroyed 30 to 40 percent of vitamin B12 in those foods. Other research showed that B12 contents of herring was reduced up to 62 percent when it was grilled, boiled, fried, steamed, and microwaved, leading the authors to suggest that “loss of vitamin B12 is dependent on the degree of temperature and time used in conventional cooking.”
Alternative reliable sources of B12
A vitamin B12 deficiency can result in significant health problems, ranging from difficulties with memory to irreversible brain damage, an increased risk of stroke, anemia, nerve damage, depression, and weakness. Therefore it is critical for everyone to ingest a sufficient amount of this nutrient.
Vegetarians and vegans (who consume no animal products) are at risk for vitamin B12 deficiency, especially if they count on plant-based sources or supplements that are not reliable. In addition, many elderly individuals have difficulty assimilating vitamin B12, while people who have various gastrointestinal problems also can have absorption challenges. Therefore the population of people who are highly susceptible to a vitamin B12 deficiency is significant.
Fortunately, there are effective alternatives.
- Fermented foods, such as tempeh (a high-protein soy and grain food), natto, and a variety of Korean products made from fermented soybeans (e.g., chungkookjang, doenjang, kochujang). Sauerkraut also is a fermented food, especially products that have been produced with the bacteria Propionibacteria.
- Edible algae, with dried green and purple lavers (nori) containing significant amount of the vitamin. However, other edible algae provide little to no vitamin B12, so be cautious about claims made by some food producers
- Wild mushrooms contain vitamin B12, but only a few varieties have been found thus far to have a significant amount; that is, black trumpet (Craterellus cornucopioides) and golden chanterelle (Cantharellus cibarius) Other more popular wild mushrooms, such as porcini, oyster, and black morels offer only a trace to no vitamin B12.
- Vegetables enriched with B12, although likely not yet available at a store near you, are another possibility. Studies show that vegetables grown in soil with organic fertilizers as well as those grown hydroponically with added B12 can be good sources of the nutrient
- For the elderly, the authors recommended including more foods fortified with vitamin B12, fish and shellfish, as well as canned clam broth
Other sources of vitamin B12 not mentioned by the authors are brewer’s yeast and nutritional yeast, which can easily be added to a wide variety of foods to boost vitamin B12 intake. When buying these yeast products, be sure the label says they have been fortified with the vitamin, and store them away from light to help ensure their potency.
Getting a sufficient amount of vitamin B12 is essential for good health and can have a significant impact on older adults. Individuals at risk for deficiency should be aware that some sources of the vitamin they may have depended on are not reliable and ensure they find viable alternatives.
Nishioka M et al. Loss of vitamin B(12) in fish (round herring) meats during varius cooking treatments. Journal of Nutritional Science and Vitaminology 2011; 57(6): 432-36
Watanabe F et al. Effects of microwave heating on the loss of vitamin B12 in foods. Journal of Agricultural and Food Chemistry 1998; 46(1): 206-10
Watanabe F et al. Biologically active vitamin B12 compounds in foods for preventing deficiency among vegetarians and elderly subjects. Journal of Agricultural and Food Chemistry 2013; 61(28): 6769-75
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