Table 3.

Biochemical profile.

Biochemical profile
		Mean (SD)	Reference values
Serum	Ca (mg/dL)	9.6 (0.8)a	8.8–10.2
	P (mg/dL)	2.1 (0.7)	1–12 months: 3.0–7.5
			1–11 years: 3.5–6.5
			11–15 years: 3.5–5.3
	Alk Phos (IU/L)	1123 (586)	1 month–6 years: 80–380
			6–12 years: 60–480
			12–15 years: 90–570 (male)
			60–280 (female)
	PTH (pg/mL)	39 (22, median)	10–69
	25-OHD (ng/mL)	37 (14)	20–50
	1,25(OH)2D (pg/mL)	254 (124)	<30 days: <10–72
			1 month–17 years: 15–90
Urine	TRP (%)b	98 (3)	<0.25 years: 61–86
			0.3–0.5 years: 68–93
			0.6–1 year: 80–89
			1–2 years: 78–93
			3–10 years: 81–98
			11–15 years: 86–99

$\text{TRP}\%=1-\left[\frac{\text{Urinary Phosphate}\times \text{Serum creatinine}}{\text{Serum Phosphate}\times \text{Urinary creatinine}}\right]\times 100$.

Abbreviations: Ca, calcium; P, phosphate; Alk Phos, alkaline phosphatase; PTH, parathyroid hormone; 25-OHD, 25 hydroxyvitamin D; 1,25(OH)₂ D, 1,25 dihydroxyvitamin D; SD, standard deviation; TRP, tubular reabsorption of phosphate. [Reference range for 1,25(OH)₂D is that in use at ESOTERIX/LabCore; reference ranges for all other serum values are those in use at Yale-New Haven Hospital. Values for TRP are those reviewed by Ardeshirpour [4].

^aValues are in Mean (SD, unless otherwise indicated).

^bn= 9 where calculable, 25 had undetectable urinary P.