Nowadays when you ask someone what factors are most important to them when choosing food, they will probably say taste, cost, the environmental impact of the food and how healthy it is in terms of whether it is ultra processed or contains high amounts of sugar and fat. But how many people evaluate the nutrient content of their food, understanding how plentiful it is in vitamins and minerals?

One specific vitamin that can be overlooked is B12, yet it is vital for every cell of our body to function properly and plays a crucial role in the nervous system, energy production and DNA synthesis. It is also easy to become deficient in, as it not only goes through a highly complex process to be absorbed but factors such as older age, low stomach acid, certain medications and medical interventions, poor gut health and vegan/vegetarian diets can all diminish how much B12 we are getting.

What does that mean?

Having a deficiency can lead to symptoms such as pale skin, fatigue, tingling, numbness or muscle weakness, gastrointestinal issues such as constipation or diarrhoea and balance and cognition problems. If left untreated, not having enough B12 can result in more serious issues such as nerve damage, heart failure and pernicious anaemia. So, ensuring you have optimum levels is clearly critical for good health.

On the other hand, according to the research, unless you have a deficiency, taking extra B12 often doesn’t provide any benefit, and in some rare cases could be harmful. Therefore, finding out you are deficient is vital for your health (as well as spending money on supplements you may not need!).

How do you find out if you are B12 deficient?

Is it as simple as having a standard blood test done? Well, not quite. And here’s why…

B12 cannot get into cells by itself and needs to be transported into them by what is known as a carrier protein. If this protein is low or not functioning properly, it will prevent this from happening. So B12 could be present in your blood but cannot enter cells and therefore cannot be utilised by the body. Therefore, a test that only measures B12 in the blood, known as a total B12 test, could show you as having normal blood levels, but has no way of showing if B12 is actually active within cells.

And so, a further test is often done if someone has normal or borderline total B12 levels but is showing signs of a deficiency. This test measures their active B12, which can not only ascertain if levels are normal but can also establish if B12 is being taken up by the cells and utilised. So, this should be enough, should it not? It would seem so, but what if you do not yet have a deficiency but levels are so low that it is only a matter of time before you do?

This is where measuring levels of Methylmalonic acid (MMA) can be beneficial (and why our test uses this marker). Referred to as a functional B12 test, MMA is only lowered when B12 has been fully absorbed, so it is also able to identify absorption issues. Generally speaking, the higher the MMA the lower your B12. If you are not deficient, an MMA test can still identify if you are low in B12 so you can correct it before it becomes a clinical deficiency. Furthermore, MMA can be measured in urine, which is not only considered more reliable than blood, but also saves you the trouble, and sometimes pain, of getting a blood test done. Additionally, you can have the test kit sent in the post, so you are able to do the test at home and then post it back to the lab. It really couldn’t be any simpler! And it could save you the stress and worry of dealing with a deficiency and potential symptoms down the line, proving that old adage, prevention is better than cure!