Table 1 The characteristics of included studies for analysis.

From: Influence of Vitamin A supplementation on inflammatory biomarkers in adults: a systematic review and meta-analysis of randomized clinical trials

Author, year

Country

Mean age

Sample size

Dose (mg)

Duration of treatment (weeks)

Health condition

Intervention type

Sex

CRP change in intervention and placebo group a

Mahdieh Abbasalizad Farhangi (2013)

Iran

36

50

25,000

16

Obese

Retinyl palmitate

F

6.24 vs, 5.51

Shaikh M Ahmad (2020)

Bangladesh

0.5

271

50,000

6

Infants

Retinol

F/M

0.38 vs, 0.41

S. A. Tanumihardjo (2020)

USA

6

93

1333

12

Low serum retinol

Retinol

F/M

0.58 vs, 0.75

Charles B Stephensen (2002)

USA

5

92

200,000

2

Pneumonia

Retinol

F/M

30 vs, 38.6

Francisco J. Rosales (2002) (a)

USA

8.5

88

200,000

2

Pneumonia

Retinol

F/M

22.03 vs, 19.37

Francisco J. Rosales (2002) (b)

USA

8.5

108

200,000

2

Pneumonia

Retinol

F/M

17.83 vs, 16.28

Trevino A Pakasi (2010) (a)

Indonesia

35

136

5000

8

TB

Retinol

F/M

4 vs, 6.4

Trevino A Pakasi (2010) (b)

Indonesia

35

136

5000

8

TB

Retinol

F/M

1.5 vs, 1.7

Trevino A Pakasi (2010) (c)

Indonesia

35

119

5000

8

TB

Retinol

F/M

4.2 vs, 6.4

Trevino A Pakasi (2010) (d)

Indonesia

35

119

5000

8

TB

Retinol

F/M

1.1 vs, 1.3

Shaikh M Ahmad (2008)

Bangladesh

23.9

36

200,000

1

Low serum retinol

Retinol

M

1.27 vs, 0.75

Ph Donnen (a) (2001)

Brussels

3

542

200,000

1

During infection

Retinyl palmitate

F/M

34.6 vs, 31.9

Ph Donnen (b) (2001)

Brussels

3

540

5000

1

During infection

Retinyl palmitate

F/M

32.2 vs, 31.9

Sima Jafarirad (2013)

Iran

32.5

35

200,000

24

MS

Retinyl palmitate

F/M

2.88 vs, 1.58

  1. Summary of clinical trials on the effects of vitamin A supplementation on inflammatory biomarker (CRP). CRP C-reactive protein, TB tuberculosis, M male, F female, a Changes in cytokine concentrations are presented by common units for CRP (mg/L).