Plasma pyridoxal 5'-phosphate in the US population: the National Health and Nutrition Examination Survey, 2003-2004

• Published in: The American journal of clinical nutrition Vol. 87; no. 5; pp. 1446 - 1454
• Main Authors: Morris, Martha Savaria, Picciano, Mary Frances, Jacques, Paul F, Selhub, Jacob
• Format: Journal Article
• Language: English
• Published: Bethesda, MD American Society for Nutrition 01.05.2008; American Society for Clinical Nutrition; American Society for Clinical Nutrition, Inc
• Subjects: administration & dosage; Adolescent; Adult; African Americans; Age Factors; Aged; Aged, 80 and over; Biological and medical sciences; Biomarkers; Biomarkers - blood; blood; Child; Child, Preschool; Diet; Dietary Supplements; dietary surveys; elderly; Enzymes; Epidemiology; Feeding. Feeding behavior; Female; Fundamental and applied biological sciences. Psychology; gender differences; homocysteine; Homocysteine - blood; Humans; Infant; Male; men; Middle Aged; National Health and Nutrition Examination Survey; nutrient intake; nutrient reserves; Nutrition; nutrition assessment; Nutrition Policy; Nutrition Surveys; Nutritional Requirements; Nutritional Status; Plasma; pyridoxal 5'-phosphate; pyridoxal phosphate; Pyridoxal Phosphate - blood; pyridoxine; Recommended Dietary Allowances; Sex Factors; United States; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Vitamin B; Vitamin B 6; Vitamin B 6 - administration & dosage; Vitamin B 6 - blood; Vitamin B 6 Deficiency; Vitamin B 6 Deficiency - blood; Vitamin B 6 Deficiency - epidemiology; women; United States; United States > US; Human; Pyridoxal phosphate; Population; Nutrition survey; Health; Blood plasma
• ISSN: 0002-9165; 1938-3207; 1938-3207
• DOI: 10.1093/ajcn/87.5.1446

BACKGROUND: No large-scale, population-based study has considered the descriptive epidemiology of vitamin B-6 status with use of plasma pyridoxal 5'-phosphate (PLP), the indicator of vitamin B-6 adequacy used to set the current Recommended Dietary Allowance, which is =1 y in the National Health and Nutrition Examination Survey (2003-2004), we considered relations between plasma PLP and various subject characteristics and examined trends in plasma PLP and homocysteine with vitamin B-6 intake, both overall and in selected subgroups. RESULTS: In males, plasma PLP decreased with age after adolescence only in nonusers of supplemental vitamin B-6. Regardless of supplement use, plasma PLP concentrations of women of childbearing age were significantly lower than those of comparably aged men, and most oral contraceptive users had plasma PLP <20 nmol/L. The prevalence of low plasma PLP was significantly >3% at vitamin B-6 intakes from 2 to 2.9 mg/d in all subgroups and at intakes from 3 to 4.9 mg/d in smokers, the elderly, non-Hispanic blacks, and current and former oral contraceptive users. Intakes from 3 to 4.9 mg/d compared with <2 mg/d were associated with significant protection from low plasma PLP in most subgroups and from hyperhomocysteinemia in the elderly. CONCLUSIONS: Vitamin B-6 intakes of 3 to 4.9 mg/d appear consistent with the definition of a Recommended Dietary Allowance for most Americans. However, at that intake level, substantial proportions of some population subgroups may not meet accepted criteria for adequate vitamin B-6 status.