Up to 30 % of the respondents had symptoms longer than 5 years before the vitamin B12 deficiency was discovered. Of these, some had symptoms for more than 20 years before diagnosis.
In only a quarter of the people the deficiency was discovered within one year after the start of the symptoms.

These results show that there is too little thought given by practitioners to a vitamin B12 deficiency as the cause of the symptoms.
When one considers that the delay in the diagnosis and treatment may cause irreversible symptoms, it is clear how important it is that practitioners test much earlier for a vitamin B12 deficiency.

The most common symptoms and the percentage of respondents who mentioned the symptoms:

• (extreme) fatigue  (87.9 %)
• concentration problems (“brain fog”) (68.9 %)
• word finding problems, misspeaking  (65.8 %)
• irritability, nervousness  (65.0 %)
• muscle weakness & myalgia  (62.5 %)
• memory problems  (60.6 %)
• feeling cold  (60.1 %)
• tingling  (57.9 %)
• dizziness  (48.7 %)
• intestinal complaints  (48.2 %)
• nerve pains, burning sensation in the legs, feet and/or arms  (45.5%)
• palpitations, heart rhythm disorders  (40.9%)
• depression  (39.9%)
• ataxia: unexplainable falling, unsteadiness, bumping agains things, etc  (35,7 %)
• a “walking on cotton wool” feeling  (35.2 %)
• shortness of breath  (35.6 %)
• menstrual problems  (23.9 %)
• inflammation of the tongue (glossitis – burning/thick/painful  tongue)  (23.6 %)
• loss of appetite, weight loss  (20.5 %)
• reduced pain sensation, reduced smell & taste  (12.6 %)

32.4 % of the people mentioned additional symptoms, including:
headache, tinnitus, miscarriages, sleeping problems, hair loss, nausea, infertility, anxiety disorders, panic attacks, increased susceptibility to illness, blurred vision, increase in urinary frequency, bruising, restless legs, pigmentation disorders, muscle cramps, derealisation, numb feeling, partial paralysis, hypersensitivity to sound and incontinence.

Serious or very serious:

Up to 81 % of the people mentioned the fatigue as serious or very serious.

Also experienced as serious or very serious:

• Concentration problems: 45.8 %
• Irritability: 45.9 %
• Muscular aches and pains, muscle weakness: 44.4 %
• Intestinal problems: 36.8 %
• Memory problems: 35.7 %
• Nerve pain: 34.7 %
• Word finding problems: 32.9 %
• Tingling: 31.2 %
• Dizziness: 30.4 %
• Depression: 29.8 %

Over 20 % of the patients with a B12 deficiency also had a folic acid and/or iron deficiency.
In this group one in four had both deficiencies.
In addition, vitamin D deficiency was frequently mentioned.

Other deficiencies which were mentioned fairly frequently were vitamin B1 & B6.
Also mentioned were: calcium, potassium, zinc, vitamin B2, vitamin B3, vitamin B5 and magnesium.