Table 1:
Participant characteristics are split based on vitamin D status and described as mean ± standard deviation for normally distributed data and median, interquartile range (IQR) for non-normally distributed data. Racial breakdown by vitamin D status is included B = Black, W = White, BR = Biracial, LX = Latinx, N = Native). For biological sex, F = Female and M = Male. For race & ethnicity and sex comparisons, we performed the Chi-Square test for the p values and Cramer’s V for effects. For all other variables, we performed One-way ANOVAs for normally distributed data and Kruskal-Wallis tests for non-normally distributed data. We report eta squared (η2) as a measure of effect size for ANOVAs and epsilon squared (ε2) for Kruskal-Wallis tests. For the physical activity variable, including average weekly steps and moderate to vigorous physical activity (MVPA), the sample sizes were: deficient (n = 20), insufficient (n = 35), sufficient (n = 54). For caffeine consumption: deficient (n = 21), insufficient (n = 40), sufficient (n = 63). Regarding pairwise comparisons for significant Kruskal Wallis tests, the vitamin D sufficient group was older (p = 0.041), exhibited lower M-index (p < 0.001), exhibited earlier sleep midpoint (p = 0.023), exhibited greater daily MVPA (p = 0.014) and steps (p = 0.006), and reported higher caffeine consumption (p < 0.001) compared to the vitamin D deficient group. The vitamin D sufficient group also reported higher caffeine consumption (p = 0.009) compared to the vitamin D insufficient group. All other pairwise comparisons were null (ps ≥ 0.061).
| Participant Characteristics | Deficient n = 22 n = 1 |
Insufficient n = 42 n = 3 |
Sufficient n = 66 n = 17 |
p | Effect Size |
|---|---|---|---|---|---|
| Supplementing | |||||
| Race/ethnicity | (14 B, 8 W) | (18 B, 19 W, 4 BR,1 LX) | (12 B, 49 W, 3 BR,1 LX, 1 N) | 0.006 | 0.288 |
| Biological sex (female/male) | (15F/7M) | (18/F24M) | (32F/34M) | 0.148 | 0.172 |
| Age, yrs | 21.0, 1.8 | 22.0, 5.8 | 22.5, 14.8 | 0.040 | 0.049 |
| Height, cm | 164, 16 | 170, 15 | 173, 15 | 0.126 | 0.032 |
| Mass, kg | 77 ± 16 | 76 ± 14 | 75.3 ± 14 | 0.848 | 0.003 |
| BMI, kg/m2 | 27, 9 | 26, 6 | 25, 4 | 0.292 | 0.019 |
| M-Index | 49, 24 | 34, 26 | 29, 8 | <0.001 | 0.141 |
| Brachial Systolic BP, mmHg | 119 ± 11 | 118 ± 9 | 117 ± 10 | 0.777 | 0.005 |
| Brachial Diastolic BP, mmHg | 71 ± 8 | 71 ± 8 | 70 ± 7 | 0.971 | 0.001 |
| Glucose, mg/dL | 86, 13 | 88, 12 | 83, 10 | 0.604 | 0.008 |
| Sleep Onset, clock hour | 00:54 ± 1:33 | 11:54 ± 1:30 | 11:54 ± 1:17 | 0.159 | 0.982 |
| Days monitored, sleep actigraphy | 7, 1 | 8, 6 | 8, 7 | 0.205 | 0.203 |
| Sleep Midpoint SD | 0.926, 1.02 | 0.864, 0.532 | 0.989, 0.591 | 0.655 | 0.008 |
| Sleep Midpoint, clock hour | 28.50, 2.50 | 27.90, 1.90 | 27.50, 1.68 | 0.023 | 0.068 |
| Average daily steps | 3713,2741 | 5243,2839 | 6187,4318 | 0.005 | 0.097 |
| Average daily MVPA | 28.9,25.3 | 34.3,29.9 | 43.3,23.6 | 0.015 | 0.078 |
| Days monitored, PA | 8,1 | 8,1 | 8,1 | 0.768 | 0.005 |
| Caffeine consumption, mg | 16.2,43 | 32.2,107 | 92,181 | <0.001 | 0.138 |
| Days monitored, caffeine | 3,3 | 6,3 | 6,3 | 0.201 | 0.026 |