Vitamin B12 is an essential nutrient our bodies need to function. Knowing about vitamin B12 and how to get enough of it for a vegetarian is critical for people transitioning to a plant-based diet.
This guide discusses vitamin B12 and why we need it. First, it explains what happens when you don't get enough and the signs of deficiency to look out for. It then looked at studies on perceptions of vegan diet deficiency and how people tested their levels. Finally, he offers tips to make sure you're getting enough to stay healthy.
Vitamin B12 is a water-soluble vitamin found naturally in animal products such as meat, dairy and eggs. The active forms of B12 are methylcobalamin and 5-deoxyadenosylcobalamin, and their precursors that can be transformed in the body are hydroxocobalamin and cyanocobalamin.
Vitamin B12 is bound to protein in food and needs stomach acid to release it so the body can absorb it. B12 supplements and fortified food forms are already free and do not require this step.
Experts recommend that children need vitamin B12 to support brain development and the production of healthy red blood cells. If children don't get enough B12, they can develop a vitamin B12 deficiency, which can lead to permanent brain damage if doctors don't treat them.
Homocysteine ​​is an amino acid derived from methionine. Elevated homocysteine ​​is a risk factor for cardiovascular disease and has been linked to diseases such as Alzheimer's disease, stroke, and Parkinson's disease. People need enough vitamin B12 to prevent high homocysteine ​​levels, as well as other essential nutrients such as folic acid and vitamin B6.
Because vitamin B12 is only reliably found in animal products, vitamin B12 deficiency can occur in those who eat a strictly plant-based diet and do not take supplements or regularly consume fortified foods.
In over 60 years of vegan experimentation, only B12-fortified foods and B12 supplements have proven to be reliable sources of B12 for optimal health, according to the Vegan Society. They note that most vegans get enough vitamin B12 to avoid anemia and neurological damage, but many vegans don't get enough vitamin B12 to minimize their potential risk of heart disease or pregnancy complications.
A process involving digestive enzymes, stomach acid, and intrinsic factor separates vitamin B12 from dietary proteins and helps the body absorb it. If this process is disrupted, someone may develop a defect. This may be due to:
The Vegetarian Society notes that there is no consistent and reliable set of symptoms that indicate vitamin B12 deficiency. However, typical deficiency symptoms include:
Since about 1–5 milligrams (mg) of vitamin B12 is stored in the body, symptoms can develop gradually over several months to a year before someone becomes aware of a vitamin B12 deficiency. However, infants usually show symptoms of vitamin B12 deficiency earlier than adults.
Many doctors still rely on blood levels of B12 and blood tests to check levels, but the Vegan Society reports that this is not enough, especially for vegans. Algae and some other plant foods contain B12 analogs that can mimic real B12 in blood tests. Blood tests are also unreliable because high folic acid levels mask the symptoms of anemia that can be detected by blood tests.
Experts suggest that methylmalonic acid (MMA) is the most sensitive marker of vitamin B12 status. In addition, people can get tested for their homocysteine ​​levels. Someone may contact their healthcare provider to inquire about these tests.
The UK National Health Service recommends that adults (19 to 64 years of age) consume about 1.5 micrograms of vitamin B12 per day.
To make sure you're getting enough vitamin B12 from a plant-based diet, the Vegetarian Society recommends the following:
B12 is best absorbed in small amounts, so the less often you take it, the more you need to take. The Vegetarian Society notes that there is no harm in exceeding the recommended amount, but recommends not exceeding 5,000 micrograms per week. In addition, people can combine options such as eating fortified foods and supplements.
Women who are pregnant or breastfeeding should make sure they have enough vitamin B12 to pass it on to their baby. Strict vegetarians should check with their doctor about taking supplements that provide enough vitamin B12 for pregnancy and lactation.
It is important to note that foods such as spirulina and seaweed are not proven sources of vitamin B12, so people should not risk developing a vitamin B12 deficiency by relying on these foods. The only way to ensure adequate intake is to eat fortified foods or take supplements.
People looking for vegan-friendly vitamin B12 fortified products should always check the packaging as ingredients and manufacturing processes may vary by product and location. Examples of vegan foods that may contain B12 include:
Vitamin B12 is an essential nutrient that people need to keep their blood, nervous system, and heart healthy. Vitamin B12 deficiency can occur if people eat a mostly plant-based diet without the addition of fortified foods or supplements. In addition, people with digestive problems, the elderly, and those taking certain medications may not absorb B12 properly even when eating animal products.
B12 deficiency can be serious, threatening the health of adults, infants, and developing embryos. Experts such as the Vegetarian Society recommend taking B12 as a supplement and including fortified foods in your diet. Since the body stores vitamin B12, it may take some time for a deficiency to develop, but a child may show symptoms sooner. People who wish to have their levels checked can contact their health care provider and may request a test for MMA and homocysteine.
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Louise is a BANT registered dietitian and author of health books. She has eaten a plant-based diet all her life and encourages others to eat right for optimal health and performance. www.headsupnutrition.co.uk