Chapter 8 - Methods for assessment of pantothenic acid (Vitamin B5)

Abstract

Pantothenic acid is an essential micronutrient required for energy metabolism. Its function is conferred by its role as a cofactor in the synthesis of coenzyme A, which is essential for fatty acids metabolism and the citric acid cycle. Deficiency is very rare due to its wide distribution in foods, presenting clinically as burning feet syndrome and only seen in cases of severe malnutrition. Due to concomitant micronutrient deficiencies seen in malnutrition, symptoms have only been specifically identified experimentally by use of pantothenic acid kinase antagonists. Symptoms relate to impaired CoA synthesis and include fatigue, apathy, and irritability. There is no evidence of toxicity, which is likely to be prevented by rapid renal clearance. Currently, there are no functional markers of pantothenic acid status, which can only be assessed by direct measurement. Various matrices can be measured with whole blood providing the best correlation with dietary intake. Methods utilize either HPLC (with either ultraviolet or fluorescence detection), LCMSMS, or immunoassay. Although cheaper than LCMSMS, HPLC methods often require complex derivatization steps prior to analysis making methods more difficult to establish and potentially less robust. Pantothenic acid is not immunogenic, therefore immunoassay methods also require a derivatization step and so it is likely that LCMSMS represents the “gold standard” technique. Because these methods are not widely implemented in clinical or research practices there is no data available on external quality assessment or method comparisons.