Study | Study design | Population | Duration of intervention | Season of intervention | Vitamin D dose and type in intervention group | Comparator group treatment | Baseline 25(OH)D (ng/ml) | Outcome | Conclusion |
---|---|---|---|---|---|---|---|---|---|
Trautveffer, 2014, Germany [47]. | Parallel RCT - double blind | 60 healthy subjects (F=36, M=24), age 20-70 yr. | 8 weeks | Winter | Fortified bread with 400 IU, vit D3 | Placebo bread | I=20±6.4 P=23.6± 12 | ↔ Iron ↔ ferritin, ↔ trans% | No effect |
Miskulin, 2015, USA [41]. | Parallel RCT - double blind | 276 CKD Patients, average age 61 yr. | 6 months | Not reported | Oral dose of 50,000 IU, vit D2 | Placebo pills | I=16.06±5.9 P=16.96±6.4 | ↔ ferritin | No effect |
Toxqui, 2015, Spain [46]. | Parallel RCT - double blind | 109 anemic women, age 18-35 yr. | 8 and 16 weeks | Not reported | Fortified dry milk with 200 IU vit D3 and 15 mg iron | Fortified dry milk with 15 mg iron | Not reported | ↓ Iron ↔ ferritin ↔ trans% ↔ Hb | No effect |
Sooragonda, 2015, India [45]. | Parallel RCT - single blind | 30 anemic subjects, age 18-65 yr. | 12 weeks | Winter | 0.6 Lakh Amp vit D3+ Amp iron | Amp normal saline + Amp iron | I=10.3±5.2 C=11.6±3.7 | ↔ ferritin ↔ Hb | No effect |
Smith, 2016, USA [44]. | Parallel RCT - double blind | 28 healthy subjects (F=22, M=6), age 18-65 yr. | 1 week | Winter | Oral dose of 250,000 IU, vit D3 | Oral placebo | I=16.75±1.9 P=16.7±2.03 | ↔ ferritin | No effect |
Smith, 2016, USA [53]. | Parallel RCT - double blind | 30 mechanically ventilated critically ill adults (F=11, M=19, average age 63.1 yr. | 4 weeks | Not reported | Enteral dose of 500,000 IU (I1) and 250,000 IU (I2) vit D3 | Enteral placebo | I1=10±90.9 I2=7±77.8 P=8 ±80 | ↑ Hb | Positive effect |
Madar, 2016, Norway [42]. | Parallel RCT - double blind | 251 healthy subjects, age 18-50 yr. | 16 weeks | Late winter | I1=tablet 1000 IU, vit D3 I2= tablet 400 IU, vit D3 | Placebo tablet | I1=10.8±6.8 I2=12.4±8.8 P=12.4±8 | ↔ Iron ↔ Hb ↔ ferritin ↔ trans% | No effect |
Hennigar, 2016, USA [40]. | Parallel RCT - double blind | 152 military trained subjects (F=55, M=98), age 18-42 yr. | 9 weeks | Winter | Fortified bar with 1000 IU vit D3 + 2000 mg calcium | Placebo bar | Not reported | ↔ Hb ↔ ferritin ↔ trans% | No effect |
Ernest, 2016, Germany [50]. | Parallel RCT - double blind | 200 hypertensive patients (F=94, M=106), average age 60.5 yr. | 8 weeks | Summer | Oral dose of 2800 IU IU/ day, vit D3 | Placebo tablet | I= 22 ± 5.6 C:20.4±5.6 | ↔ Hb | No effect |
Ernest, 2017, Germany [49]. | Parallel RCT - double blind | 172 heart failure patients (F=59, M=113), age 18-79 yr. | 36 months | Autumn, winter, spring | Oral dose of 4000 IU/ day, vit D3 | Placebo drop | I=13.2± 5.6 C:14± 2.4 | ↔ Hb | No effect |
Jastrzebska, 2017, Poland [51]. | Parallel RCT - double blind | 36 soccer player (M=36), average age 17.5 yr. | 8 weeks | Winter | Oral dose of 5000 IU/ day, vit D3 | Placebo drop | I=19.6± 3.6 C:19.2±6.4 | ↔ Hb | No effect |
Dahlquist, 2017, Columbia [48]. | Cross over RCT - single blind | 10 highly-trained cyclists men, age 18-45 yr. | 3 hours | Not reported | Sport drink with 5000 IU vit D3 + 1000 mcg vit k2 | Placebo drink | I=30± 11.2 | ↔ Iron ↔ Hb ↔ ferritin | No effect |
Walentukiewicz, 2018, Poland [52]. | Parallel RCT - double blind | 94 elderly women, average age 68 yr. | 12 weeks | Not reported | Oral dose of 28,000 IU/ week, vit D3 | Placebo drop | I=27.37±8.14 C:24.64±11.61 | ↑ ferritin | Positive effect |
Panwar, 2018, USA [43]. | Parallel RCT - double blind | 40 CKD Patients, average age 60.5 yr. | 6 weeks | Not reported | Oral dose of 0/5 mcg/ day, calcitriol | Placebo tablet | Not reported | ↔ Hb ↔ ferritin ↔ trans% | No effect |