Vitamin B6 (pyridoxal phosphate)

A vitamin B6 blood test helps determine whether or not someone is deficient in the vitamin, or has high levels. It can give the doctor clues about anemia, heart disease, lack of energy, and skin problems.

Optimal Result: 3.4 - 65.2 ug/L, or 13.76 - 263.81 nmol/L.

Deficiency: < 3.4 Marginal: 3.4 – 5.1 Adequate: > 5.1

What does B6 deficiency feel like?

In adults, vitamin B6 deficiency can cause inflammation of the skin (dermatitis) and a red, greasy, scaly rash. The hands and feet may feel numb and prickling—like pins and needles. The tongue may become sore and red, and cracks may form in the corners of the mouth. People may become confused or irritable. Well-conducted experiments have shown that vitamin B6 deficiency leads to hypothy- roidism resulting from decreased TRH synthesis in the hypothalamus. The reversal of vitamin B6 deficiency has led to normalization of thyroid hormone levels.

Because vitamin B6 is present in most foods, dietary deficiency is rare. Secondary deficiency may result from various conditions. End-stage renal diseases, chronic renal insufficiency, and other kidney diseases can cause vitamin B6 deficiency [1]. In addition, vitamin B6 deficiency can result from malabsorption syndromes, such as celiac disease, Crohn's disease, and ulcerative colitis.

What happens if your B6 is too high?

High levels of vitamin B6 can cause neurological disorders and numbness.

1. https://ods.od.nih.gov/factsheets/VitaminB6-HealthProfessional/