Glucose Metabolism Effects of Vitamin D in Prediabetes: The VitDmet Randomized Placebo-Controlled Supplementation Study

Table 1

Characteristics of the study population () at the start of the supplementation period.

Variable	Mean or median	Standard deviation or interquartile range
Age (years)^a	65.7	7.0
25(OH)D3 (nmol/L)^b	57.0	11.0
HbA1c (mmol/mol)^b	40	3
HbA1c (%)^b	5.8	2.5
Fasting glucose (nmol/L)^a	6.1	0.7
120 min glucose (nmol/L)^a	6.1	2.5
Fasting insulin (mU/L)^b	12.0	6.0
120 min insulin (mU/L)^c	61.9	62.3
HOMA2 %beta^b	82.2	24.1
HOMA2 %IS^a	70.2	39.2
HOMA2 %IR^b	1.6	0.8
Waist circumference (cm)^b	106	9
Body mass index (kg/m^2)^b	29.4	2.7
Systolic BP (mmHg)^a	144	30
Diastolic BP (mmHg)^b	92	10
Serum PTH (pg/ml)^a	42.6	12.7
Serum calcium (mM)^b	2.33	0.07
Serum creatinine (µmol/L)^a	71.7	14.5
Serum ALAT (U/L)^a	27.5	17.6
Serum GGT (U/L)^a	29.4	23.7
Serum TSH (mU/L)^a	2.6	1.7
Serum HDL cholesterol (mmol/L)^b	1.4	0.4
Serum LDL cholesterol (mmol/L)^b	3.2	0.9
Serum triglycerides (mmol/L)^a	1.3	0.7
Serum ApoA1 (g/L)^b,c	1.6	0.2
Serum ApoB (g/L)^b,d	1.0	0.2
Serum adiponectin (µg/mL)^a,c	4.8	3.3
Serum C-reactive protein (mg/L)^a,c	1.2	1.5
Plasma TNF receptor II (pg/mL)^a	2240	480
Plasma IL-6 (pg/mL)^a	1.3	0.8
Plasma IL-1 beta (pg/mL)^a	0	0
Plasma IL-1 receptor antagonist (pg/mL)^a	200	95

Median and interquartile range; ^bmean and standard deviation;; .
25(OH)D₃: 25-hydroxyvitamin D₃; ALAT: alanine aminotransferase; Apo: apoprotein; GGT: gamma-glutamyl transferase; HDL: high-density lipoprotein; HOMA: homeostatic modeling assessment; IL: interleukin; IR: insulin resistance; IS: insulin sensitivity; LDL: low-density lipoprotein; PTH: parathyroid hormone; TNF: tumor necrosis factor; TSH: thyroid-stimulating hormone.