TABLE 2.

Distribution of serum 25(OH)D according to the original and remeasured 25(OH)D concentrations per study¹

	Baseline concentrations (intervention and control group combined)										Achieved post-treatment response (intervention group only)2
	n	Mean ± SD, nmol/L	Median, nmol/L	Fifth percentile, nmol/L	25th Percentile, nmol/L	75th Percentile, nmol/L	95th Percentile, nmol/L	<30 nmol/L, %	<40 nmol/L, %	<50 nmol/L, %	n	≥50 nmol/L, %	≥75 nmol/L, %	≥100 nmol/L, %	≥125 nmol/L, %
Chel et al. (24)
Original	335	24.9 ± 10.9	23.7	10.3	18.2	29.4	45.1	76.7	91.3	97.3	136	80.9	23.5	2.9	0.7
LC-MS/MS	335	23.3 ± 11.3	20.9	10.9	16.7	26.3	42.3	82.1	93.7	97.3	136	81.0	16.1	0.7	0
Oosterwerff et al. (25)
Original	130	23.4 ± 10.7	21.5	9.0	15.0	31.3	43.9	71.5	92.3	99.2	53	79.2	17.0	0	0
LC-MS/MS	130	25.3 ± 11.0	22.5	10.5	17.5	32.0	46.2	69.2	89.2	97.7	53	81.1	15.1	0	0
Paravit (26, 27)
Original	52	34.5 ± 10.4	35.0	18.7	26.3	43.8	49.4	34.6	63.5	96.2	22	100	95.5	63.6	37.3
LC-MS/MS	51	42.6 ± 23.0	39.0	16.1	29.6	49.4	106.6	25.5	54.9	80.4	22	90.9	81.8	72.7	31.8
Styrian Vitamin D Hypertension Trial (28)
Original	200	52.8 ± 14.0	54.5	29.3	43.0	64.3	73.2	7.0	22.5	37.5	93	100	78.5	30.1	3.2
LC-MS/MS	197	45.7 ± 13.4	45.9	22.0	36.1	55.9	67.9	13.2	34.0	55.3	93	84.9	33.3	1.1	0
Tromsø BMD (29)
Original	295	70.9 ± 22.2	69.7	36.8	56.3	85.4	107.4	2.4	7.1	15.3	136	100	100	99.3	97.1
LC-MS/MS	291	64.4 ± 20.3	65.0	31.0	50.6	77.6	97.4	3.8	11.7	23.0	136	100	100	97.8	91.9
Tromsø Clamp (30)
Original	105	40.3 ± 12.8	38.6	21.0	31.0	47.4	63.0	21.9	53.3	80.0	49	100	100	91.8	79.6
LC-MS/MS	105	36.7 ± 11.1	36.6	19.8	28.1	43.6	57.3	30.5	61.9	88.6	49	100	100	89.8	46.9
Tromsø Depression (31)
Original	241	47.3 ± 15.6	45.1	25.1	36.0	55.5	77.6	10.0	34.9	62.7	120	100	100	97.5	77.5
LC-MS/MS	241	42.4 ± 13.8	40.7	23.4	32.7	50.4	59.4	16.0	49.0	73.3	120	100	99.2	85.0	49.2
Tromsø IGT (32)
Original	509	60.5 ± 21.6	57.2	31.7	45.0	72.8	97.8	3.7	14.1	33.4	242	98.8	87.6	57.4	20.2
LC-MS/MS	509	56.4 ± 18.6	53.6	30.0	44.1	68.4	86.7	4.9	16.8	39.9	242	98.3	80.6	36.8	7.0
Tromsø Obesity (33)
Original	300	53.9 ± 16.1	53.3	27.9	42.6	64.8	81.2	6.7	19.7	40.7	116	99.1	96.6	70.7	33.6
LC-MS/MS3	300	50.6 ± 17.4	48.3	24.4	38.4	62.6	84.5	11.3	27.7	53.7	116	98.3	94.8	80.2	46.6
UCC1 (34)
Original	103	56.5 ± 21.0	55.7	27.9	39.8	71.3	89.4	8.7	25.2	43.7	50	90.0	44.0	18.0	2.0
LC-MS/MS	103	50.0 ± 17.3	51.6	22.4	36.9	62.4	75.0	13.6	30.1	46.6	50	86.0	30.0	4.0	0
UCC2 (35)
Original	108	78.2 ± 31.6	71.6	32.6	57.2	90.2	146.5	1.9	6.5	17.6	52	92.3	62.3	19.6	1.9
LC-MS/MS	108	66.7 ± 22.9	62.7	33.3	52.5	75.6	114.9	1.9	7.4	21.3	52	76.9	19.2	0	0
Wicherts et al. (36)
Original	130	22.5 ± 12.1	20.4	8.3	14.8	22.5	50.8	81.3	89.9	94.2	56	41.1	7.1	1.8	0
LC-MS/MS	127	21.2 ± 10.7	18.8	8.7	14.4	24.3	46.1	84.3	92.9	96.1	56	37.9	6.9	0	0

¹For conversion of 25(OH)D from nmol/L to ng/mL, divide by 2.496. BMD, bone mineral density; IGT, impaired glucose tolerance; LC-MS/MS: liquid chromatography-tandem mass spectrometry; UCC, University College Cork; 25(OH)D, 25-hydroxyvitamin D.

²The intervention group with the highest dose of vitamin D was used in studies with >1 intervention group (i.e., Tromsø Obesity, UCC1, UCC2, and Wicherts et al.). Values indicate percentages of the intervention group with the final achieved concentrations of 25(OH)D.

³Missing data on remeasured 25(OH)D were imputed in the Tromsø Obesity study.