Vitamin B12 – what you need to know
Vitamin B12 is essential for energy, influences our mood and helps keep our nervous system healthy.
As far as vitamins go, B12 doesn’t get much airtime despite playing a significant and instrumental role in our daily health and vitality.
So why do we need it and – more importantly – where can we get this essential nutrient from?
Why do I need vitamin B12?
Deficiency in B12 can result in a form of anaemia, a condition where blood contains fewer red blood cells than normal, or less haemoglobin (used to carry oxygen around the body) than needed. We can feel fatigued as a result of our organs not getting what they need to perform optimally.
Other symptoms of B12 deficiency include a sore tongue, mouth ulcers and a yellow tinge to the skin.
Vitamin B12 is also a vital ingredient for healthy nerve cells. Some of the specific symptoms associated with anaemia caused by vitamin B12 deficiency are pins and needles, difficulty walking and problems with memory.
The body usually stores enough B12 to last around two to four years, so be aware that it can take quite a while for symptoms of a deficiency to develop after a change, in diet for example.
How much vitamin B12 do I need?
In the UK, the NHS recommends that adults need about 1.5mcg a day of B12, which is equivalent to one small chicken breast or two large eggs.
If you eat meat, dairy, fish and eggs it’s relatively easy to meet this, but whether this recommended intake is high enough is disputed.
The 1.5mcg value is a Reference Nutrient Intake (RNI) but some nutritionists also consider the EU’s Nutrient Reference Value (NRV) of a nutrient. This is because the RNI is based on the level of a nutrient needed to meet the requirements of 97.5% of the population. The NRV is estimated as the level needed to prevent deficiencies in healthy people.
The NRV for B12 is currently 2.5mcg.
If you exercise frequently, are pregnant or nursing, you may have increased requirements so it’s important to consider B12 on a case-by-case basis.
Which foods contain vitamin B12?
Foods that contain vitamin B12 include:
- Meat (especially beef liver)
- Shellfish (clams)
- Fish (mackerel, salmon and cod)
- Yeast extract (such as marmite)
- Artificially fortified foods (some breakfast cereals, soy products and plant milks)
Fruit, vegetables and grains are not naturally sources of B12. As you can see, many of the options above come from animal sources. If you follow a plant-based/vegan diet, you’ll need to supplement to ensure enough vitamin B12.
How do vegans get B12?
Reliable vegan sources of B12 include fortified goods, such as plant milks and yoghurt-style foods, breakfast cereals, and yeast extracts such as Marmite (in large amounts).
The BDA (Association of UK Dieticians) recommends that vegans eat fortified foods at least twice a day (aiming for 3mcg daily) or taking a supplement (10mcg daily or 200mcg weekly).
Supplements can be an easy and efficient option for ensuring adequate intake, as well as peace of mind!
How do I know if I’m B12 deficient?
The best way to know whether you need a top-up is to have your levels tested by your doctor. Deficiency can be diagnosed by your doctor based on symptoms and a blood test.
The normal range for B12 concentrations in the blood is 200 to 900pcg per millilitre of blood. Levels above or below this may point to an underlying condition.