From supporting your nervous system to reducing tiredness and fatigue, vitamin B12 does a lot of quiet, essential work. It's particularly important for those following plant-based diets and for older adults. Here's what B12 does, where to find it, and when a supplement can help.
What does vitamin B12 do, and why do we need it?
Vitamin B12, also called cobalamin, is an essential nutrient your body relies on for a range of important functions. It contributes to the normal function of the nervous system, to normal red blood cell formation, and to normal energy-yielding metabolism – which is why it's so strongly associated with energy and with the reduction of tiredness and fatigue. It also contributes to normal psychological function and the normal function of the immune system, and it plays a role in the process of cell division.
B12 has one genuinely unusual feature. Unlike many nutrients, your body can't readily make or store meaningful amounts of it – and it's found naturally almost only in animal products. Put those two facts together and you can see why a regular dietary source matters, and why B12 gets special attention for anyone whose diet doesn't include much in the way of animal foods.
What foods are rich in vitamin B12?
You'll find vitamin B12 in animal products: meat, fish like salmon and cod, and dairy products including milk, cheese and eggs. If you eat plenty of these, you're likely getting enough B12 from your diet alone.
Because B12 isn't found naturally in plant foods, this is the one nutrient that needs particular thought on a vegan or vegetarian diet. If you don't eat animal products, you'll need to get your B12 from fortified foods – such as some breakfast cereals and soy products – or from a daily supplement. The NHS recommends that adults aged 19–64 need about 1.5 micrograms of B12 a day.
Who should take a vitamin B12 supplement?
Most people get enough vitamin B12 from a balanced diet. But there are a few groups for whom a supplement is genuinely worth considering.
The clearest is anyone on a plant-based diet – as above, B12 is hard to get from plants alone, so vegans and vegetarians are the group most likely to need a supplement or fortified foods. Older adults are another: as we age, the body becomes less efficient at absorbing B12, so getting a reliable intake becomes more important. And if you have a condition that affects nutrient absorption, such as coeliac disease or Crohn's disease, it's worth asking your GP or pharmacist whether a supplement would help.
If you're pregnant or breastfeeding – particularly on a plant-based diet – it's worth discussing B12 with your midwife or GP, who can advise on what you need. As always with pregnancy, that's a conversation to have with a healthcare professional rather than something to self-manage.
Our vitamin B12 supplements come in a variety of forms to suit your preferences, including tablets, oral sprays, flavoured sachets, chewable tablets and liquids. You'll also find B12 in our vitamin B complex supplements, alongside all eight essential B vitamins.
Explore further
These pieces from our Discover blog pick up where this article leaves off:
- Supplements for energy support, explained – how B12 and other nutrients fit into supporting normal energy levels.
- Vegan omega-3: algae oil explained – another nutrient worth knowing about if you follow a plant-based diet.
Explore our range of vitamin B12 supplements to support normal energy release, nervous system function and the reduction of tiredness and fatigue.