Vitamin B12 and Folate Tests: Nutritional Assessment

Importance of B12 and Folate

Vitamin B12 and folate are essential nutrients for DNA synthesis, red blood cell formation, and neurological function. Deficiencies can cause pernicious anemia, neurological damage, and developmental issues. Testing helps identify nutritional deficiencies early.

Vitamin B12 Test

Functions in the Body

B12 is essential for myelin formation, DNA synthesis, and energy metabolism. It's only found in animal products, making vegetarians and vegans at risk for deficiency. B12 absorption requires intrinsic factor produced in the stomach.

Normal Ranges

Normal B12: 200-900 pg/mL. Levels below 200 pg/mL indicate deficiency. Neurological symptoms can occur even with "low-normal" levels. MMA and homocysteine tests help confirm B12 deficiency.

Causes of B12 Deficiency

• • Pernicious anemia (autoimmune)
• • Gastrointestinal surgery or disease
• • Vegetarian/vegan diet without supplementation
• • Medications like metformin and PPIs
• • Chronic alcohol use

Folate Test

Functions in the Body

Folate is crucial for DNA synthesis, cell division, and neural development. It works with B12 in methionine synthesis. Adequate folate is especially important during pregnancy to prevent neural tube defects.

Normal Ranges

Normal folate: 5.4-16 ng/mL (serum) or 140-960 nmol/L. Deficiency increases homocysteine and cardiovascular disease risk. Folate deficiency typically develops faster than B12 deficiency.

Causes of Folate Deficiency

• • Poor dietary intake (limited leafy greens, legumes)
• • Malabsorption disorders (celiac, Crohn's disease)
• • Alcohol use disorder
• • Medications (methotrexate, anticonvulsants)
• • Pregnancy and lactation

Symptoms of Deficiency

• ✓ Fatigue and weakness
• ✓ Shortness of breath and pale appearance
• ✓ Numbness and tingling (B12)
• ✓ Memory problems and difficulty concentrating
• ✓ Depression and mood changes

Who Should Be Tested?

Vegetarians and vegans, individuals with gastrointestinal disorders, older adults, those with neurological symptoms, pregnant women, and people taking medications affecting absorption should have B12 and folate testing.

Treatment and Supplementation

B12 deficiency from pernicious anemia requires B12 injections or high-dose oral supplements. Folate deficiency is treated with oral folic acid supplements. Dietary improvements and addressing underlying causes are essential for long-term management.