Charlotte Cuerq1, Noël Peretti2, Karim Chikh1, Anne Mialon3, Marc Guillaumont3, Jocelyne Drai1, Emilie Blond4. 1. Biochemistry Department, Lyon Sud Hospital, Hospices Civils de Lyon, Lyon, France INSERM U1060, CarMeN Laboratory, Lyon 1 Claude Bernard University, Oullins, France. 2. INSERM U1060, CarMeN Laboratory, Lyon 1 Claude Bernard University, Oullins, France Paediatric Nutrition Department, Hôpital Femme-Mère-Enfant, Hospices Civils de Lyon, Lyon, France Faculté de Médecine Lyon Est, Université Claude Bernard Lyon 1, UCBL, Lyon, France. 3. Biochemistry Department, Lyon Sud Hospital, Hospices Civils de Lyon, Lyon, France. 4. Biochemistry Department, Lyon Sud Hospital, Hospices Civils de Lyon, Lyon, France INSERM U1060, CarMeN Laboratory, Lyon 1 Claude Bernard University, Oullins, France emilie.blond@chu-lyon.fr.
Abstract
BACKGROUND: The pre-analytical stabilities of vitamins A, E, K, B1, B2, B6, B12, C, carotenoids and folates in whole blood were studied. The aim of this work was to provide clear and workable pre-analytical procedures specifying optimal delay before freezing for laboratories which perform themselves such analyses or which receive and transfer such specimens to referral laboratories. METHODS: The stability of vitamins was studied in whole blood at room temperature after light exposure up to 24 h (vitamin C), 48 h (vitamins A, E, B1, B2, B6 and carotenoids) and 72 h (vitamins K, B12, red blood cell (RBC) and serum folates). Vitamin C stability after baseline acidification was analysed up to 48 h. Changes observed were compared to a clinical cut-off defined as total change limit based on a combination of analytical performance and within-subject variation. RESULTS: Clinically and statistically significant changes occurred only in vitamins C (-22.5%), B6 (+9.9%) and serum folates (-16.8%) concentrations after 6, 24 and 48 h, respectively. Vitamins A, E, K, B1, B2, B12, RBC folates and carotenoids showed good stability up to 48 or 72 h. Vitamin C in acidified serum conserved at room temperature appeared unstable. The optimal condition for acidified vitamin C conservation was at less than -20℃. CONCLUSION: The majority of vitamins remain stable for up to 48 h. Vitamin C quantification requires serum acidification followed by freezing as soon as possible. Freezing, respectively, within 12 h and 24 h for determination of plasma vitamin B6 and serum folates concentrations is recommended.
BACKGROUND: The pre-analytical stabilities of vitamins A, E, K, B1, B2, B6, B12, C, carotenoids and folates in whole blood were studied. The aim of this work was to provide clear and workable pre-analytical procedures specifying optimal delay before freezing for laboratories which perform themselves such analyses or which receive and transfer such specimens to referral laboratories. METHODS: The stability of vitamins was studied in whole blood at room temperature after light exposure up to 24 h (vitamin C), 48 h (vitamins A, E, B1, B2, B6 and carotenoids) and 72 h (vitamins K, B12, red blood cell (RBC) and serum folates). Vitamin C stability after baseline acidification was analysed up to 48 h. Changes observed were compared to a clinical cut-off defined as total change limit based on a combination of analytical performance and within-subject variation. RESULTS: Clinically and statistically significant changes occurred only in vitamins C (-22.5%), B6 (+9.9%) and serum folates (-16.8%) concentrations after 6, 24 and 48 h, respectively. Vitamins A, E, K, B1, B2, B12, RBC folates and carotenoids showed good stability up to 48 or 72 h. Vitamin C in acidified serum conserved at room temperature appeared unstable. The optimal condition for acidified vitamin C conservation was at less than -20℃. CONCLUSION: The majority of vitamins remain stable for up to 48 h. Vitamin C quantification requires serum acidification followed by freezing as soon as possible. Freezing, respectively, within 12 h and 24 h for determination of plasma vitamin B6 and serum folates concentrations is recommended.
Authors: Kerry S Jones; Sarah R Meadows; Karen Chamberlain; Damon A Parkington; Dave Collins; Polly Page; Albert Koulman Journal: J Nutr Date: 2021-11-02 Impact factor: 4.798