As well as offering my clients personal training, I’ve also advised them on nutrition for the last 12 years, because you need both exercise and good nutrition for optimum health and fitness.
In this blog post I’ll focus on one vitamin, which is much talked about in the context of vegan diets, because most vegans have a hard time getting enough if it. What’s the vitamin? It’s vitamin B12.
Vitamin B12 is a water-soluble vitamin, and it plays many important roles in your body. It helps folate (another B vitamin) to make red blood cells, vital for transporting oxygen around your body and generating energy in your cells. That’s why fatigue is a classic symptom of vitamin B12 deficiency.
For your body to absorb vitamin B12, you need something called intrinsic factor, a compound made in your stomach. Lack of intrinsic factor can lead to pernicious anemia, a disease which damages red blood cell production and also harms your nervous system which affects muscle function among other things.
Why is vitamin B12 so important to your nervous system? It helps build and maintain the sheaths which surround your nerve fibres, so any deficiency can lead to depression, decreased brain function such as poor memory, and nerve damage.
Vitamin B12 has other roles, such as promoting healthy bone marrow, and on a genetic level in the production of DNA. It also plays a vital role in metabolism of all food groups.
Best food sources of vitamin B12
The richest sources of this vitamin are protein foods: fish, red meat, and dairy.
Chicken liver and sardines are two of the best sources. Eggs are a good source, but not as good as many people think, due to a compound in eggs which reduces vitamin B12 absorption. Tuna and sirloin steak are also good sources, indeed most red meat is rich in easily absorbed vitamin B12.
For vegetarians, cottage cheese is a good option. Strict vegetarians and vegans are advised to take vitamin B12 supplements under the supervision of a registered dietitian or doctor, as there are no plant-based food sources of vitamin B12. There are some vegan foods which are now fortified with vitamin B12, but you need to make sure you are eating enough to meet the body’s needs.
Dominic Londesborough is a personal trainer in London with 12 years experience, who offers online nutrition coaching for a one-off payment of £25.00.