Vitamins A, B1, B6, and C
Davis’s Laboratory and Diagnostic Tests Online, powered by Unbound Medicine, provides nurses and students access to 400+ test monographs containing reference ranges, indications, patient preparation and result interpretation. Explore these free sample topics:
-- The first section of this topic is shown below --
Vitamin A: retinol, carotene; vitamin B1: thiamine; vitamin B6: pyroxidine, P-5′-P, pyridoxyl-5-phosphate; vitamin C: ascorbic acid.
To assess vitamin deficiency or toxicity to assist in diagnosing nutritional disorders such as malabsorption; disorders that affect vision, skin, and bones; and other diseases.
Serum collected in a red-top tube each for vitamins A and C; plasma collected in a lavender-top (EDTA) tube each for vitamins B1 and B6.
(Method: High-performance liquid chromatography)
|Vitamin||Age||Conventional Units||SI Units|
|Vitamin A||(Conventional Units × 0.0349)|
|Birth–1 yr||14–52 mcg/dL||0.49–1.81 micromol/L|
|1–6 yr||20–43 mcg/dL||0.7–1.5 micromol/L|
|7–12 yr||26–49 mcg/dL||0.91–1.71 micromol/L|
|13–19 yr||26–72 mcg/dL||0.91–2.51 micromol/L|
|Adult||30–120 mcg/dL||1.05–4.19 micromol/L|
|Vitamin B1||(Conventional Units × 29.6)|
|Serum or plasma||0.21–1 mcg/dL||6.2–30 nmol/L|
|Whole blood||2.5–7.5 mcg/dL||74–222 nmol/L|
|Vitamin B6||(Conversion Factor × 4.046)|
|5–30 ng/mL||20–121 nmol/L|
|Vitamin C||(Conventional Units × 56.78)|
|0.6–1.9 mg/dL||34.1–107.9 micromol/L|
|Vitamin B1, vitamin B6, and vitamin C levels tend to decrease in older adults.|