Table 2.
An overview of the studies included in the systematic review and meta‐analysis
| Study | Sample size (sex), n | Age (years) | Serum 25(OH)D status at baseline (nmol L−1) [mean (SD)] | Method used for analysing 25(OH)D | Study duration | Study design | Comparator | Form and dosage of vitamin D | Calcium supplement (mg) | Physical performance measure |
|---|---|---|---|---|---|---|---|---|---|---|
| Bischoff‐Ferrari (2012) 42 | 20 (females) |
C: 63.45 (7.78) I: 59.48 (6.27) |
C: 35.45 (9.03)c
I: 30.7 (10.2)c |
HPLC‐MS/MS | 4 months | Randomised, double‐blinded trial |
C: 800 IU D3 day−1
C: 5600 IU D3 week−1 |
I: 20 μg HyD day−1
I: 140 μg HyD week−1 |
Non |
TUG (3 m) Knee extension Knee flexion strength Repeated sit‐to‐stand |
| Ceglia (2013) 34 | 21 (females) |
C: 80 (5) I: 76 (4) |
C: 48.3 (8.8) I: 43.6 (10.3) |
RIA (DiaSorin Inc., Stillwater, MN, USA) | 4 months |
Randomised, double‐blind, placebo‐controlled Single centre |
Placebo | 4000 IU (D3) day−1, oral | Non (dietary intake was assessed) |
Knee extension SPPB (incl. 4 m TUG) |
| Dhesi (2004) 48 | 139 |
C: 76.6 (6.1) I: 77.0 (6.3) |
C: 25.0b (23.8–26.3) I: 26.8b(25.5–28.0) |
IDS Gamma‐B 25‐OH immunoassay (IDS, Tyne & Wear, UK) | 6 months | Randomised, double‐blind, placebo‐controlled | Placebo | 600 000 IU (D2) × 1 bolus inj. | Non |
Quadriceps strength AFPT |
| Glendenning 2012 49, a | 686 (females) |
C: 76.5 (4) I: 76.9 (4) |
C: 66.5 (27.1) I: 65.0 (17.8) |
Liaison method (DiaSorin Inc.) | 3, 6 and 9 months | Randomised, double‐blind, placebo‐controlled | Placebo | 150 000 IU (D3) every 3 months, oral | Advice: 1300 (supp./diet) |
Grip strength (kg) TUG (3 m) |
| Grady (1991) 51, a | 98 |
C: 78.9 (5.4) I: 79.4 (5.4) |
C: 65.7 (51.4) I: 60.4 (35.3) |
Microassay by Reinhart et al., 1984 | 1, 2, 4, 8, 12, 18 and 24 weeks | Randomised, double‐blind, placebo‐controlled | Placebo | 0.5 μg (1,25‐dihydroxyvitamin D3) day−1, oral | Non (dietary intake was assessed) |
Grip strength (kg) Leg muscle strength |
| Janssen (2010) 53, a | 70 (females) |
C: 79.2 (6.7) I: 82.4 (4.9) |
C: 34.3 (11.5) I: 32.6 (11.6) |
NA | 6 months | Randomised, double‐blind, placebo‐controlled | Placebo | 400 IU (D3) day−1, oral | 500 |
Knee extension Hand grip strength (kg) LEP TUG (4 m) Modified Cooper test |
| Kenny (2003) 52, a | 65 (men) | 76 (4) |
C: 60 (18)c
I: 65 (18)c |
Competitive protein binding (Endocrine Science Inc., Calabasas Hills, CA, USA) | 6 months | Randomised, double‐blind, placebo‐controlled | Placebo | 1000 IU (D3) day−1, oral | 500 |
Leg extension strength Grip strength (kg) SPPB (incl. 3 m TUG) |
| Lagari (2013) 44, a | 86 | 73.4 (6.4) | 82.5 (25.0)c | LC/MS/MS | 6 months | Randomised, double‐blinded trial | 400 IU D3 day−1, oral | 2000 IU (D3) day−1, oral | Calcium supplements was assessed |
Grip strength (kg) Gait speed |
| Lips (2010) 43 | 593 |
C: 77.6 (6.6) I: 78.5 (6.2) |
C: 35.3 (13.8)c
I: 34.3 (11.0)c |
Reversed phase HPLC by Lensmeyer et al., 2006 | 16 weeks | Randomised, double‐blind, placebo‐controlled Multicentre | Placebo | 8400 IU (D3) week−1, oral | 500 for those with dietary intake <1000 mg | SPPB |
| Pfeifer (2009) 45, a | 242 | 77 (4) |
C: 54 (18) I: 55 (18) |
RIA (Immunodiagnostic Systems, Boldon, UK) | 12 and 20 months | Randomised, double‐blind, placebo‐controlled Multicentre | Placebo | 800 IU (D3) day−1, oral | 1000 |
Quadriceps strength (isometric leg extensor strength) TUG (3 m) |
| Pirotta (2015) 50, a | 26 |
C: 71.5 (5.7) I: 66.1 (4.0) |
C: 48.5 (11.1) I: 46.4 (11.4) |
Liaison method (DiaSorin) | 10 weeks | Randomised, double‐blind, placebo‐controlled | Placebo | 2000 IU (D3) day−1, oral | Non |
Knee extensor Stair climbing power FSST TUG (3 m) |
| Songpatanasilp (2009) 46 | 72 (females) | 70.60 (4.30) | 69.98 (19.18)c | RIA (DiaSorin) | 12 weeks | Randomised placebo‐controlled trial | Placebo | 0.5 mg (20 000 IU) (alfacalcidiol) day−1, oral | 1500 | Quadriceps strength (isokinetic dynamometer) |
| Wood (2014) 38, a | 305 (females) | 63.8 (2.2) |
Normal: 34.3 (14.7) Overweight: 33.9 (14.3) Obese: 32.4 (16.3) |
LC/MS/MS (Chromsystems, UK) | 12 months (bimonthly study visits) | Randomised, double‐blind, placebo‐controlled | Placebo |
I: 400 IU (D3) day−1, oral I: 1000 IU (D3) day−1, oral |
Non | Grip strength (kg) |
| Xia (2009) 55, a | 142 (females) |
C: 70.4 (3.6) I: 70.4 (3.9) |
NA | NA | 6 and 12 months | Randomised, multicentre, open‐label, placebo‐controlled | 125 IU (Calcitriol) day−1, oral | 125 IU + 0.25 μg (Calcitriol) day−1, oral | 600/600 |
Grip strength (kg) FTFFT |
| Zhu (2010) 47, a | 302 (females) |
C: 77.0 (4.8) I: 77.6 (4.2) |
C: 44.3 (13.0)c
I: 45.3 (12.5)c |
RIA (DiaSorin) | 6 and 12 months | Randomised, double‐blind, placebo‐controlled | Placebo | 1000 IU (D2) day−1, oral | 1000 |
TUG (3 m) Lower limb muscle strength (ankle, knee, hip) |
a
Included in the meta‐analysis.
b
Geometric mean and 95% confidence interval.
c
Calculated to nmol L−1using coefficient of 2.5.
AFPT, aggregate functional performance time; C, control; FSST, the four square step test; FTFFT, Five‐times‐sit‐to‐stand‐test; HPLC, high‐performance liquid chromatography; HyD, 25‐hydroxyvitamin D3; I, intervention; LC/MS/MS, liquid chromatography, tandem mass spectrometry; LEP, Leg extension power; NA, not available; RIA, radioimmunoassay; SPPB, Short Physical Performance Battery; TUG, timed‐up‐and‐go.