Table 1.

Wide variability in Vitamin D dose and duration, type of patients enrolled, and whether anemia was present or not in randomized clinical trials

	Patients	Anemia	Vitamin D dose	Vitamin D duration	Total Vitamin D dose
Trautveffer 2014	Healthy adults	No	Fortified bread with 400 IU vit D3 daily	8 weeks	22,400 IU vit D3
Miskulin 2016^a	Adults with CKD	Yes	Oral dose of 50,000 IU vit D2 weekly	6 months	1,200,000 IU vit D2
Toxqui 2013	Adult Women	Yes	Fortified milk with 200 IU vit D3 & 15 mg iron daily	16 weeks	22,400 IU vit D3
Sooragonda 2015	Healthy adults	Yes	0.6 Lakh Amp vit D3+ Amp iron once	Once	600,000 IU vit D3
Smith 2017 [7]^a	Healthy adults	No	Oral dose of 250,000 IU, vit D3 once	Once	250,000 IU vit D3
Smith 2018 [6]	Critically ill adults	Yes	Enteral dose of 50,000 IU (I1) or 100,000 IU (I2) vit D3 daily	5 days	500,000 IU (I1) vit D3 250,000 IU (I2) vit D3
Madar 2016	Healthy adults	No	I1 = tablet 1000 IU, vit D3 daily I2 = tablet 400 IU, vit D3 daily	16 weeks	42,000 IU (I1) vit D3 16,800 IU (I2) vit D3
Hennigar 2016	Healthy adults	No	Fortified bar with 1000 IU vit D3 + 2000 mg calcium, 2 bars per day	9 weeks	126,000 IU vit D3
Ernest 2016	Adults with hypertension	No	Oral dose of 2800 IU vit D3 daily	8 weeks	156,800 IU vit D3
Ernest 2017	Adults with heart failure	Some (23 of 172)	Oral dose of 4000 IU vit D3 daily	36 months	4,032,000 IU vit D3
Jastrzebska 2017	Healthy adults	No	Oral dose of 5000 IU vit D3 daily	8 weeks	280,000 IU vit D3
Dahlquist 2017	Healthy adults	No	Sport drink with 5000 IU vit D3 once	Once	5000 IU vit D3
Walentukiewicz 2018^a	Elderly women	No	Oral dose of 28,000 IU vit D3 weekly	12 weeks	336,000 IU vit D3
Panwar 2018	Adults with CKD	Yes	Oral dose of 0.5 mcg (20 IU vit D3) calcitriol daily	6 weeks	840 IU vit D3

CKD Chronic kidney disease

^aHemoglobin not reported