Table 3.
Influence of dietary vitamin D concentrations on selected serum parameters.
| Dietary vitamin D concentrations in study food, IU/kg | |||||||
|---|---|---|---|---|---|---|---|
| Serum chemistry parameter | Reference range | 795.7 | 3087.3 | 5510.9 | 7314.0 | 9992.5 | p-value |
| Creatinine, mg/dL | 0.50–1.03* | ||||||
| Initial | 0.67 (0.03) | 0.68 (0.03) | 0.78 (0.03) | 0.69 (0.03) | 0.66 (0.03) | ||
| Change from baseline | 0.05 (0.04) | 0.04 (0.03) | 0.08 (0.03) | 0.07 (0.03) | 0.06 (0.03) | 0.95 | |
| BUN, mg/dL | 7.1–25.6* | ||||||
| Initial | 13.1 (1.0) | 12.7 (1.0) | 12.8 (1.0) | 11.6 (1.0) | 11.5 (1.0) | ||
| Change from baseline | 1.8 (1.1) | 3.3 (1.1) | 2.5 (1.1) | 2.4 (1.1) | 0.9 (1.1) | 0.57 | |
| Albumin, mg/dL | 2.8–4.0* | ||||||
| Initial | 3.62 (0.03) | 3.56 (0.03) | 3.72 (0.03) | 3.76 (0.03) | 3.58 (0.03) | ||
| Change from baseline | −0.1 (0.08) | 0.20 (0.08) | 0.05 (0.08) | 0.16 (0.08) | 0.18 (0.08) | 0.20 | |
| Hematocrit, % | 44.8–55.6* | ||||||
| Initial | 49.5 (1.7) | 49.3 (1.7) | 51.0 (1.7) | 49.0 (1.7) | 48.0 (1.7) | ||
| Change from baseline | 1.3 (1.7) | 0.4 (1.7) | −0.7 (1.7) | 1.9 (1.7) | 1.2 (1.7) | 0.85 | |
| Hemoglobin, mg/dL | 14.8–19.1* | ||||||
| Initial | 17.0 (0.03) | 17.2 (0.03) | 17.8 (0.03) | 16.9 (0.03) | 16.7 (0.03) | ||
| Change from baseline | 0.55 (0.63) | 0.01 (0.63) | −0.26 (0.63) | 0.86 (0.63) | 0.74 (0.63) | 0.67 | |
| Alkaline phosphatase, U/L | 23–185* | ||||||
| Initial | 67.8 (13.4) | 100.9 (13.4) | 69.1 (13.4) | 62.6 (13.4) | 64.4 (13.4) | ||
| Change from baseline | −0.1 (8.8) | −2.9 (8.8) | −3.9 (8.8) | −1.4 (8.8) | −4.4 (8.8) | 0.99 | |
| Phosphorus mg/dL | 2.2–5.6* | ||||||
| Initial | 4.02 (0.21) | 3.45 (0.210) | 3.51 (0.210) | 3.51 (0.21) | 3.67 (0.21) | ||
| Change from baseline | −0.50 (0.24) | 0.06 (0.24) | 0.46 (0.24) | 0.39 (0.24) | 0.28 (0.24) | 0.06 | |
| Calcium, mg/dL | 9.1–11.6* | ||||||
| Initial | 10.0 (0.1) | 9.9 (0.1) | 10.2 (0.1) | 10.1 (0.1) | 10.2 (0.1) | ||
| Change from baseline | 0.22 (0.13) | 0.53 (0.13) | 0.36 (0.13) | 0.54 (0.13) | 0.18 (0.13) | 0.60 | |
| Ionized calcium, mM | 1.25–1.45† | ||||||
| Initial | 1.38 (0.03) | 1.38 (0.03) | 1.40 (0.03) | 1.38 (0.03) | 1.37 (0.03) | ||
| Change from baseline | 0.01 (0.02) | 0.03 (0.02) | 0.01 (0.02) | 0.02 (0.02) | −0.01 (0.02) | 0.51 | |
| PTH, pM | 1.1–10.6† | ||||||
| Initial | 2.03 (0.47) | 1.56 (0.47) | 1.28 (0.47) | 2.81 (0.47) | 3.43 (0.46) | ||
| Change from baseline | −0.55 (0.48) | 0.26 (0.28) | −0.02 (0.48) | −1.26 (0.48) | −0.46 (0.38) | 0.24 | |
| 25(OH) vitamin D3, nM | 109–423† | ||||||
| Initial | 300 (33.0) | 261 (33.5) | 264 (37.6) | 320 (30.1) | 316 (30.6) | ||
| Change from baseline | −45.7 (37.6)a | 93.2 (37.6)b | 141.2 (37.6)b | 110.8 (37.6)b | 119.9 (37.6)b | 0.01 | |
All values are means (standard errors). *Normal range from the colony. †Reference ranges from the Michigan State University Veterinary Diagnostic Laboratory (18). BUN, blood urea nitrogen; PTH, parathyroid hormone. a,bMeans with different superscripts are different (p < 0.05).