Table 1.
Demographics of all study participants.
Figure 1.
African-Americans and Native Americans have decreased 25(OH)D levels.
(A) Median 25(OH)D levels for African-Americans (n = 125), Native Americans (n = 179), and European-Americans (n = 470). Error bars represent interquartile range. ***p<0.001, Kruskal-Wallis test with Dunn's multiple comparison; p<0.05, Shapiro-Wilk and D'Agostino normality test. (B) Frequency of vitamin D severe deficiency (<12 ng/mL) and vitamin D deficiency (12–20 ng/mL) in African-Americans, Native Americans, and European Americans. Each symbol represents one individual.
Figure 2.
Male gender in European-Americans, increased BMI in females, and UV index in Native Americans are associated with vitamin D status.
(A) Median 25(OH)D levels in males vs. females stratified by ancestral background. ****p<0.0001, Mann Whitney test; p<0.05, Shapiro-Wilk and D'Agostino normality test. (B) Median 25(OH)D levels in normal weight (BMI<25), overweight (BMI 25–30), obese (BMI 30–40), and morbidly obese (BMI>40) individuals stratified by gender. **p<0.01, ***p<0.001, Kruskal-Wallis test with Dunn's multiple comparison; p<0.05, Shapiro-Wilk and D'Agostino normality test. Error bars indicate interquartile range. (C) Mean 25(OH)D levels of individuals based upon the average UV index during the month in which their biological sample was obtained stratified by ethnicity. Error bars indicate SD; *r2 = 0.04, p<0.05. (D) Mean 25(OH)D levels of individuals based upon the average UVB 305 nm during the month in which their biological sample was obtained stratified by ethnicity. Error bars indicate SD.
Table 2.
Univariate analysis of study participants with 25(OH)D values <20 ng/mL and >20 ng/mL.
Table 3.
Multivariate logistic regression model.
Figure 3.
Vitamin usage and estrogen supplementation are associated with increased vitamin D levels.
(A) Percentage of individuals that reported taking vitamins or not taking vitamins with 25(OH)D levels <20 ng/mL or >20 ng/mL. ****p<0.0001, Fisher's exact test. (B) Levels of 25(OH)D observed in individuals with self-reported vitamin use (n = 46) or no vitamin use (n = 728). Median 25(OH)D levels with interquartile range is shown. ***p<0.001, Mann Whitney test; p<0.05, Shapiro-Wilk and D'Agostino normality test. (C) Percentage of European-American female study participants that reported estrogen supplementation. *p<0.05, Fisher's exact test. (D) Levels of 25(OH)D in European-American female study participants with self-reported estrogen supplementation (n = 63) or no estrogen supplementation (n = 474). Median vitamin D levels with interquartile range are shown. **p<0.01, Mann Whitney test; p<0.05, Shapiro-Wilk and D'Agostino normality test.
Figure 4.
GM-CSF concentration was reduced in the vitamin D sufficient group.
(A) Cytokine concentration ratio of vitamin D sufficient group to vitamin D severely deficient group. **p<0.01, Mann Whitney U Test. (B) Median concentration of GM-CSF in vitamin D severely deficient (n = 20) and sufficient groups (n = 20). *p<0.05, Mann-Whitney U Test corrected for BMI; p<0.05, Shapiro-Wilk and D'Agostino normality test. Error bars indicate interquartile range.
Table 4.
Demographics of the European-American individuals selected for cellular and biomarker assays.
Figure 5.
Activated CD4+ and CD8+ T cell levels are increased in the vitamin D sufficient group.
(A) Percentage of activated CD4+ T cells (CD4+CD38+) in both vitamin D sufficient (n = 20) and severely deficient (n = 20) groups are shown. Mann Whitney U Test. (B) Percentage of activated CD8+ T cells (CD8+CD38+) in both vitamin D sufficient (n = 17) and severely deficient (n = 18) groups are shown. *p<0.05, Mann Whitney U Test; p<0.05, Shapiro-Wilk and D'Agostino normality test. Median and interquartile range are shown.
Figure 6.
Phosphorylated STAT1 responses to IL-2 was increased in both CD4+ T cells and B cells from vitamin D sufficient group.
(A) Median STAT1 phosphorylation (pSTAT1) fold changes after IFN-γ, IL-2, IL-10, and IL-21 stimulation in CD4+ T cells from both vitamin D sufficient (n = 11) and severely deficient (n = 11) groups. (B) Median STAT1 phosphorylation fold changes after IFN-γ, IL-2, IL-10, and IL-21 stimulation in CD8+ T cells from both vitamin D sufficient (n = 17) and deficient (n = 16) groups. (C) Median STAT1 phosphorylation fold changes after IFN-γ, IL-2, IL-10, and IL-21 stimulation in CD19+ B cells from both vitamin D sufficient (n = 11) and severely deficient (n = 11) groups. Mann Whitney U Test. *q<0.05 after BMI and multiple testing correction; p<0.05, Shapiro-Wilk and D'Agostino normality test. Error bars indicate interquartile range.