Table 1 Summarize the main features and findings of the included studies

Gaede et al. (2001) [95]

T2DM who have stable HbA1c control (no more than 10% change over the previous 2 months)

N:29

58.7 ± 7.3

Vitamin C  + Vitamin E

Vitamin C (1250 mg/d)  + Vitamin E (680 IU/d)

Placebo

4 weeks

UAE SCr

Double-blind

Farvid et al. (2005) [96]

Diabetes for at least 1 year, with a bias toward those who were not macroalbuminuric and hypertensive

N:76 P:M(9) F(10) M:M(8) F(10) V:M(9) F(11) MV:M(9) F(10)

P:50 ± 9 M:52 ± 8 V:50 ± 9 MV:50 ± 9

M (Zinc sulphate  + magnesium oxide) V (Vitamin C + Vitamin E) MV (Zinc sulphate  + magnesium oxide  + Vitamin C + Vitamin E)

M (Zinc sulphate 15 mg  + magnesium oxide 100 mg) V (Vitamin C 100 mg + Vitamin E 50 IU); MV (Zinc sulphate 15 mg + magnesium oxide 100 mg + Vitamin C 100 mg + Vitamin E 50 IU)

Placebo

3 months

UAE

Double-blind

Giannini et al. (2007) [89]

IDDM patients with microalbuminuria

N = 20

18.87 ± 2.91

Vitamin E

1200 mg/day

Placebo

6 months

UAE

Double-blind

Parham et al. (2008) [92]

NIDDM patients with microalbuminuria

N:42 I:M(62%) F(38%) C:M(52%) F(48%)

I:52.0 ± 9.3 C:54.5 ± 9.2

Zinc

30 mg/day

Placebo

3 months

UAE HbA1c

Double-blind

Khajehdehi, et al. (2011) [97]

Type 2 diabetic nephropathy (proteinuria ≥ 500 mg/day)

N:40 I:M(9) F(11) C:M(13) F(7)

I:52.9 ± 9.2 C:52.6 ± 9.7

Turmeric

Each meal containing 500 mg

Placebo

2 months

SCr UAE UACR

Double-blind

Fallahzadeh, et al. (2012) [98]

Patients with type 2 diabetes with macroalbuminuria (urinary albumin excretion 300 mg/24 h)

N:60 I:M(15) F(15) C:M(13) F(17)

I:55.9 ± 8.3 C:57.6 ± 7.5

Silymarin

420 mg/d

Placebo

3 months

SCr HbA1c MDA UACR

I:7 C:2

Double-blind

Noori et al. (2013) [99]

Patients with type II diabetes

N:34 I:M(7) F(10) C:M(6) F(11)

I:60.0 ± 2.0 C:61.0 ± 3.0

Lipoic acid and pyridoxine

lipoic acid 800 m/d and pyridoxine 80 mg/d

Placebo

12 weeks

MDA UAE

Double-blind

Haghighat et al. (2014) [90]

Patients with T2DM and FBS > 126 mg/dl

N:45 I:M(5) F(18) C:M(7) F(15)

I:55.9 ± 5.9 C:55.2 ± 5.6

Tocotrienol -enriched canola oil

200 mg/day

pure canola oil

8 weeks

UAE

Double-blind

Zhu et al. (2016) [93]

Patients with T2D

N:160

I:56.5 ± 9.8 C:57.3 ± 10.3

Telmisartan  + probucol

500 mg/dose

Telmisartan

24 weeks

SCr HbA1c UAE

I:5 C:5

Double-blind

Bahmani et al. (2016) [100]

Diabetic renal disease with proteinuria level of > 0·3 g/24 h

N:60 I:30 C:30

40–85

Se supplements

200 µg/d

Placebo

12 weeks

MDA HbA1c

Double-blind

Borges et al. (2016) [101]

DM type 1 or 2, and had persistent micro- or macroalbuminuria

N:47 I:M(11)F(12) C:M(16) F(8)

I:63(60–65) C:59(49–63)

ACE inhibitors and/or ARBs plus GTP

maximum dose (corresponding to 800 mg of EGCG)

ACE inhibitors and/or ARBs plus placebo

12 weeks

UACR UAE HbA1c

I:2 C:1

Double-blind

Elbarbary et al. (2018) [102]

Diabetic renal disease with a proteinuria level > 0.3 g/24 h

N:50 I:M(8) F(17) C:M(8) F(17)

I:61.1 ± 11.3 C:61.6 ± 10.1

Coenzyme Q10

100 mg/day

placebo

12 weeks

UAE HbA1c UACR

Double-blind

Aghadavod et al. (2018) [103]

Patients with diabetic nephropathy, despite oral angiotensin-converting enzyme inhibitors

N:90 I:M(20) F(25) C:M(23) F(22)

I:12.4 ± 3.4 C:13.3 ± 2.8

Carnosine

500 mg

Placebo

3 months

HbA1c UACR SCr MDA

Double-blind

Gholnari et al. (2018) [104]

T2DM and referred to a diabetes clinic with newly diagnosed confirmed albuminuria were evaluated or inclusion in the study

N:60 I:M(14) F(16) C:M(13) F(17)

I:56.8 ± 9.7 C:55.7 ± 10.8

Resveratrol

500 mg/day

Placebo

90 days

UACR HbA1c SCr MDA

Double-blind

Tan et al. (2019) [105]

Patients with DN

N:54 I:M(8) F(19) C:M(9) F(19)

I:62.2 ± 9.8 C:64.5 ± 9.2

Vitamin E

800 mg/d

Placebo

12 weeks

HbA1c

Double-blind

Sattarinezhad et al. (2019) [106]

T2DM who have stable HbA1c control (no more than 10% change over the previous 2 months)

N:54 I:M(18) F(9) C:M(17) F(10)

I:59 ± 10 C:62.8 ± 11.6

Tocotrienol-rich vitamin E

Tocovid 200 mg

Placebo

12 weeks

SCr HbA1c MDA

I:13 C:15

Double-blind

Satari, et al. (2021) [107]

Diabetic patients who are reviewed on a regular basis

N:59 I:M(20) F(11) C:M(18) F(10)

I:66(13) C:70(13)

Tocotrienol-rich vitamin E

200 mg/twice daily

Placebo

12 months

UACR HbA1c

I:3

Double-blind

Koay et al. (2021) [94]

DN, glomerular filtration rate 15 to 89 mL/minute/1.73m2, moderate blood pressure

N:46 I:M(13) F(9) C:M(14) F(10)

I:66.9 ± 6.9 C:64.3 ± 7.7

Melatonin

10 mg/d

Placebo

12 weeks

MDA

Double-blind

Jaafarinia et al. (2022) [108]

Patients aged ≥ 18 years with T2DM

N:40 I:M(12) F(9) C:M(11) F(8)

I:63.86 ± 10.62 C:62.68 ± 9.84

crocin

15 mg

Placebo

90 days

HbA1c UACR UAE SCr

I:1 C:1

Triple-blind