What vitamin deficiency causes tingling in hands and feet

You’ve been getting numbness and tingling into your hands, legs, or feet.  You’ve been to physiotherapists, chiropractors, massage therapists, neurologists, and acupuncturists.  Nothing is helping.  Could the cause of your numbness and tingling be a vitamin B12 deficiency even though you have been told by your MD your lab results are normal? 

Vitamin B12 and your nerves

Your brain and nerves send electrical signals to all of your body parts so they work properly.  For those signals to work properly, your nerves need to be protected or insulated by what is called a myelin sheath.  Myelin would be similar to the sheath or plastic on the electrical wires in your house.  

Vitamin B12 is a vital component in the formation and maintenance of your myelin sheath.  Being deficient in Vitamin B12 can cause damage to your myelin sheath which will disrupt nerve signals to and from your brain.  One of the common symptoms because of myelin damage related to vitamin B12 deficiency is numbness and tingling in the hands and feet.

One of the common symptoms because of myelin damage related to vitamin B12 deficiency is numbness and tingling in the hands and feet.

Other symptoms of vitamin B12 deficiency 

Beside numbness and tingling in your hands or feet you may experience the following (1):

• “brain fog” or difficulty with thinking and memory loss
• fatigue
• weakness
• problems with walking, coordination, or balance 
• swollen, inflamed tongue
• yellow skin (jaundice)
• paranoia or hallucinations

How do you know if you are deficient in vitamin B12?

Unfortunately, at the time of this writing, vitamin B12 isn’t checked routinely by your medical doctor.  If it is checked, it will be done by measuring your levels in the blood.  However, the lab ranges conventional medicine uses to measure vitamin B12 are low.  Because of these two issues, vitamin B12 deficiency is often under-diagnosed.  

A quick note about lab ranges: conventional lab ranges are designed to detect clinical disease, whereas functional lab ranges are designed to promote optimal health or catch a health problem before it is too late to fix.  So you want your lab markers to be in the functional range.

If vitamin B12 is found to be low in the blood that is considered to be the final stage of B12 deficiency.  By the time the last stage rolls around, signs and symptoms of vitamin B12 deficiency become more obvious.  Numbness and tingling (peripheral neuropathy) or brain fog do not appear until the final stage.  This is very important because by the time symptoms like this appear it may be too late to reverse them.

Numbness and tingling (peripheral neuropathy) or brain fog do not appear until the final stage of vitamin B12 deficiency.  This is very important because by the time symptoms like this appear it may be too late to reverse them.

It’s important to make sure your vitamins B12 levels are in a higher range and that the following markers are checked if they are available where you are living:

Stage 1 and 2 deficiency 

A lab marker called HoloTC (holotranscobalamin-2) will be reduced.  Even though this marker is considered to be the most sensitive marker for B12 deficiency, at the time of this writing, it is not readily available.

Stage 3 deficiency

A lab marker in the blood called homocysteine will be high. Homocysteine can also be high with folate deficiency so folate should also be measured to rule that out.  These are widely available markers.

Homocysteine

Conventional range: 0–15 µmol/L

Functional range: < 7 µmol/L

Folate

Conventional range: >10 nmol/L (> 3 μg/L)

Functional range: >18.1 nmol/L (> 8 μg/L)

A lab marker in the blood or urine called MMA (methylmalonic acid) will be high.  Measurements in urine would be more sensitive if you do not have kidney problems.  This marker isn’t readily available where I am from, but is available through a private lab.

MMA (methylmalonic acid)

BLOOD/SERUM

Conventional range: 0–378 nmol/L

Functional range: < 300 nmol/L

URINE

<2.2 ug/mg

 Stage 4 deficiency

Where I am from (Edmonton, Alberta, Canada) the conventional lab range is 120-150 pmol/L (163-203 pg/mL).  People can experience the effects of vitamin B12 deficiency in a range of 156-258 pmol/L (211-350 pg/mL). (2)  As mentioned, the conventional lab ranges are designed to detect disease rather than detecting a problem before it turns into a disease.  There is the possibility you have been told your B12 is normal.  Yet, you’re not feeling well and have signs and symptoms of vitamin B12 deficiency.

Again, you want to make your B12 levels in your blood (serum) are in a higher range.  The functional range you want to be in for serum B12 is 332-1476 pmol/L (450-2000 pg/mL).

You want to make your B12 levels in your blood (serum) are in a higher range.  The functional range you want to be in for serum B12 is 332-1476 pmol/L (450-2000 pg/mL)

As well, once you get to stage 4 deficiency you can get macrocytic anemia.  So you will see other markers such as a low red blood cell count, low hemoglobin, low hematocrit, and elevated MCV, MCHC, MCH, and RDW.

Reference for stages of Vitamin B12 deficiency (3)

Summary

Numbness and tingling in the hands, legs, or feet is a common symptom.   Vitamin B12 deficiency is one of the main causes of numbness and tingling.  Vitamin B12 is vital for your brain and nerves to function properly.  Make sure you get your B12 blood levels checked and other markers if possible.  The earlier you detect if you have vitamin B12 deficiency the easier it is to fix.

In future articles, I will discuss other important functions of vitamin B12, causes of vitamin B12 deficiency, and treatments to get your levels optimized. (causes and treatments)