Low circulating pyridoxal 5'-phosphate (PLP) concentrations have been linked to inflammatory markers and the occurrence of inflammatory diseases. However, the implications of these findings are unclear. The measurement of PLP and C-reactive protein (CRP) in blood samples collected from participants in the 2003-2004 NHANES afforded us the opportunity to investigate this relationship in the general U.S. population. Dietary and laboratory data were available for 3864 of 5041 interviewed adults, 2686 of whom were eligible (i.e. provided reliable dietary data and were not diabetic, pregnant, lactating, or taking hormones or steroidal antiinflammatory drugs). Vitamin B-6 intake was assessed using 2 24-h diet recalls and supplement use data. After multivariate adjustment for demographics, smoking, BMI, alcohol use, antioxidant vitamin status, intakes of protein and energy, and serum concentrations of creatinine and albumin, high vitamin B-6 intake was associated with protection against serum CRP concentrations >10 mg/L compared with < or =3 mg/L. However, plasma PLP > or =20 nmol/L compared with <20 nmol/L was inversely related to serum CRP independently of vitamin B-6 intake (P < 0.001). Among participants with vitamin B-6 intakes from 2 to 3 mg/d, the multivariate-adjusted prevalence of vitamin B-6 inadequacy was <10% in participants with serum CRP < or =3 mg/L but close to 50% in those with serum CRP > 10 mg/L (P < 0.001). In conclusion, higher vitamin B-6 intakes were linked to protection against inflammation and the vitamin B-6 intake associated with maximum protection against vitamin B-6 inadequacy was increased in the presence compared to absence of inflammation.

Low vitamin B-6 status, based on plasma concentrations of pyridoxal-5-phosphate (PLP), has been identified in inflammatory diseases, including cardiovascular disease, rheumatoid arthritis, inflammatory bowel disease, and diabetes. Our objective was to examine the association between plasma PLP and multiple markers of inflammation in a community-based cohort [n = 2229 participants (55% women, mean age 61 ± 9 y)]. We created an overall inflammation score (IS) as the sum of standardized values of 13 individual inflammatory markers. Multivariable-adjusted regression analysis was used to assess the associations between the IS and plasma PLP. Geometric mean plasma PLP concentrations were lower in the highest tertile category of IS relative to the lowest (61 vs. 80 nmol/L; P-trend < 0.0001). Similarly, the prevalence of PLP insufficiency was significantly higher for participants in the highest compared with the lowest tertiles for IS categories. These relationships persisted after accounting for vitamin B-6 intake. Also, there were significant inverse relationships between plasma PLP and 4 IS based on functionally related markers, including acute phase reactants, cytokines, adhesion molecules, and oxidative stress. In addition, secondary analyses revealed that many of the individual inflammatory markers were inversely associated with plasma PLP after adjusting for plasma C-reactive protein concentration. This study, in combination with past findings, further supports our hypothesis that inflammation is associated with a functional deficiency of vitamin B-6. We discuss 2 possible roles for PLP in the inflammatory process, including tryptophan metabolism and serine hydroxymethyltransferase activity.

The Dietary Guidelines for Americans (DGA) aim to reduce chronic diseases. Inflammation is an established risk factor for Type 2 diabetes, hypertension, and CVD. We examined cross‐sectional associations between adherence to the 2010 DGA and inflammation among 2,200 Framingham Offspring study participants (mean age 61.3 years, 46% male). Adherence to the 2010 DGA was assessed by the 2010 Dietary Guidelines for Americans Index (DGAI_2010), possible range 0 worst to 100 maximum adherence (mean 59.1, range 24.3–86.3). Eleven inflammatory biomarkers were ranked and compiled into an inflammation score (IS): CRP, ICAM, CD40P, IL‐6, MCP1, MPO, P‐Selectin, TNFR2, OPG, and LPL‐A2 mass and activity, possible range 0 lowest to 11 highest level of inflammation (mean 4.9, range 1.4–8.9). Using multivariable linear regression, we observed an inverse association between continuous DGAI_2010 and IS adjusted for age, sex, BMI, smoking and NSAIDS use (p<0.001). Analysis of adjusted means IS by quintiles of the DGAI_2010 (quintile means 43.2, 53.5, 59.7, 65.6 and 73.3) showed lower IS in the highest two DGAI_2010 categories (IS means 4.7 and 4.8) vs lowest (IS mean 5.1) with Tukey adjustment (p<0.001). Greater adherence to the 2010 DGA may decrease chronic disease prevalence due to reduced risk of inflammation. Supported by grants from NIH (N01‐HC 25195, RO1 HL64753; R01 HL076784; R01 AG028321) and USDA (agreement 58–1950‐0–014).