Table 3 Associations between levels of vitamin B12, folate, vitamin D and homocysteine and measures of muscle strength, gait, balance and neuropathy

Average dominant-leg strength (kgf) (both genders)

21.50 ± 8.40

22.70 ± 11.02

ns

17.22 ± 11.6

23.4 ± 9.2

ns, (0.06)

20.36 ± 7.05

22.78 ± 10.7

ns

20.22 ± 6.21

24.29 ± 12.55

ns

Average non-dominant-leg strength (kgf) (both genders)

21.64 ± 12.0

21.84 ± 10.60

ns

19.39 ± 14.58

22.33 ± 10.19

ns

18.93 ± 7.66

22.70 ± 11.95

ns

19.92 ± 6.51

23.72 ± 14.39

ns

Average leg strength (kgf) (men)

26.21 ± 2.78

27.16 ± 11.48

ns

25.76 ± 19.20

26.96 ± 10.7

ns

21.7 ± 10.5

27.90 ± 11.96

ns

22.31 ± 6.43

31.96 ± 14.4

<0.05

Average leg strength (kgf) (women)

17.63 ± 4.36

16.72 ± 5.31

ns

14.04 ± 5.14

18.18 ± 4.36

<0.05

18.49 ± 4.79

16.50 ± 4.83

ns

17.67 ± 4.19

16.62 ± 5.49

ns

Average leg strength/BMI (m²) (men)

1.09 ± 0.44

1.09 ± 0.49

ns

0.95 ± 0.61

1.11 ± 0.45

ns

0.92 ± 0.42

1.13 ± 0.47

ns

0.91 ± 0.24

1.30 ± 0.57

<0.05

Average leg strength/BMI (m²) (women)

0.74 ± 0.24

0.72 ± 0.25

ns

0.54 ± 0.22

0.79 ± 0.22

<0.05

0.73 ± 0.21

0.73 ± 0.26

ns

0.74 ± 0.23

0.72 ± 0.27

ns

Average dominant hand-grip strength (kgf) (both genders)

20.38 ± 8.45

23.23 ± 7.70

ns

19.99 ± 10.84

22.50 ± 7.32

ns

21.02 ± 8.69

22.34 ± 7.94

ns

20.05 ± 5.26

24.11 ± 9.97

ns, (0.06)

Average non-dominant hand-grip strength (kgf) (both genders)

19.32 ± 7.64

20.10 ± 7.54

ns

18.76 ± 10.60

20.01 ± 6.70

ns

20.26 ± 7.26

19.60 ± 7.68

ns

18.37 ± 5.04

21.27 ± 9.37

ns

Average grip strength (kgf) (men)

23.52 ± 9.67

26.86 ± 6.24

ns

30.39 ± 10.38

24.74 ± 7.23

ns

28.43 ± 7.06

24.92 ± 7.93

ns

21.34 ± 4.79

30.40 ± 7.85

<0.001

Average grip strength (kgf) (women)

16.75 ± 3.91

15.78 ± 2.69

ns

13.07 ± 2.56

17.28 ± 2.82

<0.01

16.31 ± 3.62

16.19 ± 3.22

ns

16.93 ± 3.62

15.53 ± 2.87

ns

Average grip strength/BMI (m²) (men)

0.97 ± 0.33

1.08 ± 0.34

ns

1.12 ± 0.29

1.03 ± 0.34

ns

1.18 ± 0.30

1.00 ± 0.34

ns

0.87 ± 0.22

1.24 ± 0.33

<0.01

Average grip strength/BMI (m²) (women)

0.71 ± 0.24

0.67 ± 0.14

ns

0.51 ± 0.14

0.75 ± 0.17

<0.01

0.64 ± 0.16

0.71 ± 0.21

ns

0.67 ± 0.15

0.72 ± 0.23

ns

Michigan Neuropathy Screening Instrument (history: maximum severity of 13 points)

2.04 ± 1.71)

1.72 ± 1.35

ns

2.18 ± 1.66

1.78 ± 1.48

ns

1.79 ± 1.12

1.88 ± 1.62

ns

2.00 ± 1.65

1.70 ± 1.35

ns

Michigan Neuropathy Screening Instrument (physical assessment: maximum severity of 10 points)

2.10 ± 1.62)

2.73 ± 1.56

ns

3.27 ± 1.49

2.27 ± 1.58

ns, (0.06)

2.57 ± 1.33

2.43 ± 1.90

ns

2.19 ± 1.52

2.76 ± 1.66

ns

Neurothesiometer VPT score right foot (V)

13.73 ± 6.01

11.8 ± 4.39

ns

15.11 ± 5.90

12.02 ± 4.88

ns

12.86 ± 4.87

12.55 ± 5.34

ns

14.18 ± 6.21

10.96 ± 3.13

<0.05

Neurothesiometer VPT score left foot (V)

15.50 ± 8.44

13.09 ± 6.42

ns

17.30 ± 8.17

13.34 ± 7.05

ns

15.32 ± 7.25

13.72 ± 7.46

ns

14.93 ± 8.08)

13.26 ± 6.59)

ns

Neurothesiometer VPT score average (V)

14.61 ± 6.95

12.44 ± 4.84

ns

16.21 ± 6.34

12.68 ± 5.61

ns

14.09 ± 5.77

13.14 ± 5.97

ns

14.55 ± 6.71)

12.11 ± 4.63)

ns

History of having fallen at least once in the preceding year

7 (Yes)

7 (Yes)

ns

5 (Yes)

9 (Yes)

ns

4 (Yes)

10 (Yes)

ns

9 (Yes)

5 (Yes)

ns

17 (No)

25 (No)

6 (No)

36 (No)

10 (No)

32 (No)

20 (No)

22 (No)

29 % (Yes)

22 % (Yes)

45 % (Yes)

20 % (Yes)

29 % (Yes)

24 % (Yes)

31 % (Yes)

19 % (Yes)

Barthel Index of Activity of Daily Living (maximum score of 20)

19.62 ± 1.05

19.78 ± 0.49

ns

19.09 ± 1.37

19.87 ± 0.46

<0.01

19.64 ± 0.84

19.74 ± 0.77

ns

19.82 ± 0.48)

19.62 ± 0.98

ns

3 (<20)

6 (<20)

5 (<20)

4 (<20)

<0.05 (Fish)

3 (<20)

6 (<20)

5 (<20)

4 (<20)

21 (=20)

26 (=20)

6 (=20)

41 (=20)

11 (=20)

36 (=20)

24 (=20)

23 (=20)

13 % (<20)

19 % (<20)

45 % (<20)

9 % (<20)

21 % (<20)

14 % (<20)

17 % (<20)

15 % (<20)

Lawton Instrumental Activities of Daily Living (maximum score of 8)

7 (<8)

4 (<8)

ns

5 (<8)

6 (<8)

<0.05 (Chi)

4 (<8)

7 (<8)

ns

9 (<8)

2 (<8)

<0.05 (Fish)

17 (=8)

28 (=8)

6 (=8)

39 (=8)

<0.05 (Fish)

10 (=8)

35 (=8)

20 (=8)

25 (=8)

29 % (<8)

14 % (<8)

45 % (<8)

13 % (<8)

29 % (<8)

17 % (<8)

31 % (<8)

7 % (<8)

Performance-Oriented Mobility Assessment–Balance (POMA B) (maximum score of 16)

6 (<16)

10 (<16)

ns

6 (<16)

10 (<16)

<0.05 (Chi)

6 (<16)

10 (<16)

ns

9 (<16)

7 (<16)

ns

18 (=16)

22 (=16)

5 (=16)

35 (=16)

ns, (Fish)

8 (=16)

32 (=16)

20 (=16)

20 (=16)

25 % (<16)

31 % (<16)

55 % (<16)

22 % (<16)

43 % (<16)

24 % (<16)

31 % (<16)

26 % (<16)

Performance-Oriented Mobility Assessment–Gait (POMA G) (maximum score of 12)

8 (<12)

9 (<12)

ns

6 (<12)

11 (<12)

ns, (0.05),(Chi)

5 (<12)

12 (<12)

ns

8 (<12)

9 (<12)

ns

16 (=12)

23 (=12)

5 (=12)

34 (=12)

ns, (Fish)

9 (=12)

30 (=12)

19 (=12)

20 (=12)

33 % (<12)

28 % (<12)

55 % (<12)

24 % (<12)

36 % (<12)

29 % (<12)

30 % (<12)

31 % (<12)

Timed up-and-go test (s) (average of two trials) (both genders)

11.02 ± 5.02

10.01 ± 4.16

ns

14.17 ± 6.29

9.53 ± 3.52

<0.01

11.63 ± 6.37

10.05 ± 3.74

ns

10.70 ± 4.66

10.17 ± 4.45

ns

Timed up-and-go test (s) (average of two trials) (men)

9.46 ± 2.67

9.56 ± 2.84

ns

11.59 ± 3.86

9.18 ± 2.43

ns

9.91 ± 3.98

9.44 ± 2.48

ns

9.52 ± 2.40

9.54 ± 3.16

ns

Timed up-and-go test (s) (average of two trials) (women)

12.33 ± 6.19

10.52 ± 5.34

ns

15.65 ± 7.17

9.93 ± 4.48

<0.05

12.58 ± 7.43

10.78 ± 4.83

ns

11.97 ± 6.11

10.75 ± 5.45

ns

6-m fast-gait speed (m/s) (average of two trials) (both genders)

1.07 ± 0.31

1.12 ± 0.26

ns

0.88 ± 0.30

1.15 ± 0.25

<0.01

1.03 ± 0.32

1.12 ± 0.27

ns

1.07 ± 0.28

1.12 ± 0.28

ns

6-m fast-gait speed (m/s) (average of two trials) (men)

1.19 ± 0.29

1.16 ± 0.27

ns

1.00 ± 0.28

1.20 ± 0.27

ns

1.10 ± 0.28

1.19 ± 0.28

ns

1.17 ± 0.25

1.17 ± 0.31

ns

6-m fast-gait speed (m/s) (average of two trials) (women)

0.97 ± 0.29

1.06 ± 0.26

ns

0.81 ± 0.31

1.09 ± 0.23

<0.05

1.00 ± 0.34

1.03 ± 0.24

ns

0.97 ± 0.29

1.07 ± 0.26

ns