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B vitamin deficiencies are a LOT more common than we thought

The Heights 2020 nutrient deficiency trial found staggering deficiencies in B vitamins. Here’s why that’s so important.

September 01, 2021
8 min read

In the Heights 2020 nutrient deficiency trial, we discovered that a high percentage of people were severely deficient in B vitamins. So, we gave them Heights to see what happened. We saw a 100% improvement of B vitamin levels across the board. And a reported 120% improvement in mood. Result. 

Article breakdown

How common are vitamin B deficiencies?

In the results of the first Heights 2020 trial, conducted by our in-house clinical dietitian, Sophie Medlin, we found that: 

  • 71% of people were deficient in thiamine (vitamin B1)

  • 93% of people were deficient in riboflavin (vitamin B2)

This is a huge breakthrough discovery. 

Here’s why:

It’s generally accepted by the medical community that deficiencies in B vitamins such as thiamine (B1) and riboflavin (B2) are very rare. In fact, in Sophie’s 14-year career, she has never seen tests being done for vitamins B1 and B2. 

Why are these results so important?

“These B vitamin test results give us a great indication of the modern and current status of B vitamins in the UK,” explains Sophie.

“And it really helps to explain why so many people are experiencing suboptimal mental function, mental performance, as well as general symptoms like brain fog and other things, which previously have been a bit of a mystery. Now we have a bit more of an idea as to why that might be and we can continue to explore and raise awareness among the general medical community.”

Why are we discovering B vitamin deficiencies now?

B vitamins are predominantly found in animal sources, although there are a few plant-based sources. But due to a combination of modern farming practices and more people moving away from omnivorous diets, B vitamin deficiencies are becoming much more common than we previously thought. 

“That means that our healthcare professionals aren’t testing for these deficiencies routinely,” cautions Sophie, “but if they did, it’s much more likely that they would find them. The guidance on which vitamins we’re likely to be deficient in is generally considered to be out of date.”

The reasons for B vitamin deficiency

Extensive farming practices, climate change, erosion, fertilised soil and waterlogging all negatively impact soil, reducing its ability to grow nutritious crops. Therefore, where B vitamins would historically be found in some plant-based sources, they are now growing in soils that are more depleted of nutrients. So B vitamins (and many other nutrients) can be less available in plant-based foods than they used to be. 

Why do we need B vitamins? 

B vitamins are vital for:

  • Energy

  • Metabolism

  • Mental health

  • Mood

  • Production of melatonin (the hormone that encourages sleep)

Even common symptoms like lethargy, lack of focus, and low mood (all rife in 2020 and 2021) could all be impacted by B vitamin deficits that, until now, we didn’t know existed.

“B vitamins are essential for all of the nervous system functions in our body,” says Sophie. “That includes the way that our brain cells communicate with one another to pass information around, and how our brain communicates with other parts of our body—picking up messages like touch, sound, and anything that is related to experiencing the world around us.”

The symptoms of B vitamin deficiencies

When our B vitamin levels are low, or when we aren't getting enough B vitamins in our diet, we can end up experiencing a negative impact on our mental health as well as the rest of our nervous system. 

This could lead to us experiencing unusual symptoms like changes in taste, visual disturbances, and physical sensations like tingling hands and feet. Because B vitamins are so important for our overall physical function—when we reduce the amount available in our diet it has a profound effect on our whole bodies. 

Back to the B vitamin blood test results

We tested 14 people, aged 25–55, with a fairly even split of women and men, omnivores and vegans. We measured our results in a lab at baseline and, again, at nine months. 

We tested five different B vitamins (B1, B2, B6, B9, B12). And, if you’re curious—a detailed breakdown of what we found is included in the appendix. 

Highlights of B vitamin test results

  • 100% of B vitamin deficiencies were improved

  • Of the 23 deficiencies across all of the B vitamins analysed, 83% were corrected

  • Levels of all five B vitamins improved by an average of 24%

Want to know more about B vitamins? Learn all about them here.

B vitamins and mood blood test results

Measuring mood improvements is a delicate business. To make sure we got a good sense, we used a few different methods. Three psychosocial questionnaires were conducted at baseline, at three months, and again at nine months. The questionnaires implemented were all subjective, self-reporting measures designed to provide a clear picture of an individual’s mental state. 

Although there were improvements across all three surveys between each of the time points, McNair’s 1971 Profile of Mood States (POMS) questionnaire indicated particularly interesting results. The POMS questionnaire contains 65 statements that describe how the participant has been feeling over the last week. Questions are based around six themes: anger, confusion, depression, fatigue, tension and vigour.

As energy and mood are common symptoms of B vitamin deficiency, the mean scores for these variables—energy and depression (i.e. mood)—were broken down between baseline and follow-up. Between baseline and three months, there was a 36% improvement in energy levels, with an additional 40% improvement in depression (mood) scores.

The total score (scores combined from all six themes) showed a 111% improvement between baseline and three months, and a 120% improvement between baseline and nine months!

Want to explore your own B vitamin levels? 

If you’re experiencing symptoms such as brain fog, low mood, and low energy, and haven’t been able to find an explanation, then exploring your B vitamin levels could be an interesting option. 

(Many of our customers report feeling huge improvements in those areas. See what they’ve had to say here.)

At the moment, you can request to have vitamin B12 levels tested by your GP, as well as your levels of folic acid—but most GPs will be less familiar with testing other B vitamin levels. 

While your GP might not be happy to pay for B vitamin testing—unless it is clinically indicated (i.e. you have signs of deficiency)—you can have a blood test done privately or through a registered dietitian.

What we’re hoping is that studies like this will help to make this kind of testing more common, and in turn discover underlying deficiencies, to help more people feel better, every day. 

Learn more about how the Heights Smart Supplement could help you. 

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Appendix: B vitamin test: baseline vs follow-up

B1 (Thiamine)


  • Supports mood

  • Stronger memory

  • Improves concentration

  • Increases energy 

  • Better sleep

Baseline results:

10 of the 14 participants (71%) were deficient or borderline deficient.

Follow-up results:

By follow-up, 93% of the sample’s scores improved across all three conditions (deficient, borderline deficient and normal range), with 80% of scores moving into the normal range from those who were deficient or borderline deficient at baseline. 

B2 (Riboflavin)


  • Boosts energy levels

  • Improves sleep

  • Enhances brain function

  • Reduces headaches

  • Supports nervous system and mood

Baseline results:

13 (93%) participants were deficient or borderline deficient.

Follow-up results:

By follow-up, 100% of scores improved in those who were deficient or borderline deficient, with 85% of scores being corrected—moving from borderline deficient or deficient to normal range. 



  • Increases alertness

  • Balances mood

  • Lowers stress and anxiety 

  • Improves recall and learning 

  • Enhances mental clarity

Baseline results:

At baseline, all participants’ blood biochemistry scores were within the normal range.

Follow-up results:

Although there were no deficiencies or borderline deficiencies at baseline or follow-up, 64% of the sample’s scores did improve. 

B9 (Folic acid)


  • Improves mood

  • Boosts energy levels

  • Stronger focus and attention

  • Better memory

  • Reduces brain fog

Baseline results:

At baseline, all participants’ blood biochemistry scores were within the normal range.

Follow-up results:

Although there were no deficiencies at baseline or follow-up, 86% of the sample’s scores did improve.



  • Balances mood

  • Improves memory

  • Combats fatigue 

  • Strengthens immune system

  • Enhances sleep

  • Reduces brain fog and confusion

Baseline results

Baseline results were generally good with only 4 borderline deficiencies, all among the vegan participants. This may have been due to fortification of B12 in vegan products or more messaging around the risk of B12 deficiency for vegans.

Follow-up results:

All but one participant remained in the normal range between baseline and follow-up, with 86% of participants showing improvements in their blood biochemistry scores.

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