Vitamin B12 and folate are needed to make healthy red blood cells and to keep your nervous system working. Deficiency is common and very treatable.
Symptoms of deficiency
Fatigue, a sore or smooth tongue, pins-and-needles, poor balance and difficulty concentrating. B12 deficiency in particular can affect nerves, sometimes before anemia appears.
The link with your blood count
Both deficiencies enlarge red blood cells, so a high MCV on your CBC is a classic clue that prompts B12 and folate testing.
Who is at risk
- Vegetarians and vegans (B12 comes mainly from animal foods)
- Older adults and people on long-term acid-reducing or diabetes medication
- People with coeliac disease or other absorption problems
Treatment is usually straightforward — dietary changes, tablets or injections, depending on the cause and severity.
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This article is for general education only and is not medical advice. Reference ranges vary between laboratories — always read your result against the range on your own report and discuss it with your doctor.