Table 4 MR analysis of the causal association of plasma vitamin C levels with AD, AD proxy phenotype, and cognitive performance using 11 genetic variants including the rs174547 variant

IGAP AD

IVW

0.93

0.80−1.09

3.85E−01

Weighted median

1.01

0.83−1.23

9.25E−01

MR-Egger

1.09

0.85−1.40

4.90E−01

MR-PRESSO

0.93

0.81−1.08

3.80E−01

UK Biobank AD proxy

IVW

0.93

0.88−0.98

7.00E−03

Weighted median

0.92

0.87−0.97

2.00E−03

MR-Egger

0.91

0.85−0.98

9.00E−03

MR-PRESSO

0.93

0.88−0.98

2.30E−02

Maternal AD group from UK Biobank

IVW

0.89

0.84−0.94

7.29E−05

Weighted median

0.87

0.82−0.93

3.30E−05

MR-Egger

0.87

0.80−0.94

1.00E−03

MR-PRESSO

0.89

0.85−0.93

6.65E−04

Paternal AD group from UK Biobank

IVW

1.02

0.92−1.12

7.59E−01

Weighted median

1.00

0.92−1.10

9.25E−01

MR-Egger

0.99

0.86−1.14

9.08E−01

MR-PRESSO

1.02

0.92−1.12

7.66E−01

Cognitive performance

IVW

0.007

[−0.043, 0.057]

0.775

Weighted median

−0.012

[−0.050, 0.026]

0.546

MR-Egger

−0.019

[−0.100, 0.061]

0.638

MR-PRESSO

0.007

[−0.043, 0.057]

0.781