Are you getting enough vitamin B12?

You may have read all about B group vitamins and their important role in human health. Vitamin B12 is one of our most important B vitamins, so let's dive into more detail about this essential nutrient. 

What is vitamin B12? 

Vitamin B12 is crucial in nervous system functioning, regulating DNA, and is involved in the formation of red blood cells. 

Like all B group vitamins, vitamin B12 is a water-soluble vitamin and it's not naturally stored in the body. So it is important that, through a varied and healthy diet, you are getting enough vitamin B12.

Foods sources rich in vitamin B12 include beef liver and red meat, clams, oysters, tuna, salmon, and dairy.  

How much vitamin B12 do you need? 

Vitamin B12 is a micronutrient, so we’re talking micrograms rather than grams. This, however, doesn’t make it any less important. The amount of amount B12 you need each day varies depending on your age and gender:

The recommended daily intake (RDI) for children is:

• 0.9 microgram/day aged 1-3 years 
• 1.2 microgram/day aged 4-8 years
• 1.8 microgram/day 9-13 years 
• 2.4 microgram/day 14-18 years  

For adults, the RDI is: 

• 2.4 microgram/day for women which increases to 2.6ug/day when pregnant and again to 2.8 µg/day when breastfeeding
• 2.4 microgram/day for men 

Deficiency signs and symptoms

Vitamin B12 is an essential mineral that plays a key role in health and wellbeing. If you're not getting enough vitamin B12 through your diet it can increase the risk of deficiency.

Vitamin B12 is essential in red blood cell formation. Signs of a B12 deficiency can manifest as anemia with symptoms of lack of energy, tiredness and pale skin. Other symptoms of deficiency may include numbness and tingling in the extremities.  

Who is at risk of deficiency, and when do you need a supplement?

Since we get almost all of our B12 from animal foods, those following a strict vegetarian or vegan diet are at a higher risk of deficiency.

Though fortified breakfast cereals and fortified nutritional yeast are readily available sources of vitamin B12, supplementation may also be necessary. 

Our body’s ability to absorb B12 is an important factor when accessing deficiency. B12 relies on adequate stomach acid because this acid activates what is known as “intrinsic factor”. Intrinsic factor binds to vitamin B12 in the small intestine allowing absorption to take place further down the GI tract.

Deficiency is especially common in the older population, primarily due to their lack of stomach acid. Studies suggest that daily supplementation may be effective in correcting deficiency and may help maintain normal levels over time. 

It’s not just older adults who are at risk of low stomach acid. The use of proton pump inhibitors reduces stomach acid secretions, leading to malabsorption. People with gastrointestinal conditions, including inflammatory bowel disease or coeliac disease, may be at risk of malabsorption further down the GI tract in the small intestines. 

If you are at risk of vitamin B12 deficiency, you may consider taking preventive measures to ensure adequate intake of this vitamin. This may include a daily supplement. 

Vitamin supplementation should not replace a balanced diet. They can only be of assistance if the dietary intake is inadequate, and if you believe you may be deficient in vitamin B12 always consult your health professional first. 

Reviewed by the healthylife Advisory Board December 2021