Monday, November 2, 2026Independent supplement reviews. No scores, no paid placements.

B12 Deficiency Symptoms: Signs, Causes and Testing

B12 deficiency symptoms card from The Well Brew listing the adult daily need of 2.4 mcg, the 200 pg/mL low blood level and common signs such as fatigue and tingling.

B12 deficiency symptoms include tiredness, weakness, pale skin, shortness of breath, a sore red tongue and numb or tingling hands and feet. Memory, mood and balance problems can follow, sometimes before anemia shows. Older adults, vegans, people with pernicious anemia and long-term metformin or acid reducer users face the highest risk. A blood test confirms it, with levels under 200 to 250 pg/mL usually counted as low.

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The Well BrewSupplement reviews, brewed slow

Slow, plain-language supplement reviews. We read the label, compare each dose with the research and work out the real cost. Edited by Maya Ellison.

The Well Brew is general information, not medical advice. Dietary supplements are not reviewed by the FDA for safety or effectiveness before they are sold. Talk to your doctor before you start, stop or combine supplements. Some links are affiliate links: if you buy through them we may earn a commission at no extra cost to you, and it never changes what we report.