Vitamin D Supplementation and Cognition in People with Type 2 Diabetes: A Randomized Control Trial
Table 1
Participant characteristics.
Low dose ()
High dose ()
Total ()
Sex
Male
1 (6.7%)
4 (27%)
5 (17%)
Female
14 (93%)
11 (73%)
25 (83%)
Mean age (SD)
55.62 (10.14)
55.80 (9.68)
55.71 (9.74)
Mdn years of education (IQR)
14 (12 – 15)
14 (13 – 16)
14 (13 – 15)
Race
White
5 (33%)
4 (27%)
9 (30%)
Black or African American
8 (53%)
9 (60%)
17 (57%)
Asian
0
1 (6.7%)
1 (3.3%)
Native Hawaiian or other Pacific Islander
1 (6.7%)
0
1 (3.3%)
Multiracial
1 (6.7%)
1 (6.7%)
2 (6.7%)
Ethnicity
Not Hispanic or Latino
10 (67%)
13 (87%)
23 (77%)
Hispanic or Latino
4 (27%)
2 (13%)
6 (20%)
Unknown or not reported
1 (6.7%)
0
1 (3.3%)
Duration of diabetes
<6 months
2 (13%)
0
2 (6.7%)
6-12 months
0
2 (13%)
2 (6.7%)
1-5 years
2 (13%)
2 (13%)
4 (13%)
5-10 years
6 (40%)
4 (27%)
10 (33%)
>10 years
5 (33%)
7 (47%)
12 (40%)
Mdn vitamin D levels in ng/mL (IQR)
Total vitamin D
Baseline
21 (15 – 25)
25 (19 – 28)
24 (17 – 27)
Week 13
27 (23 – 32)
53 (49 – 64)
42 (27 – 53)
Serum vitamin D3 (25 OH-D)
Baseline
21 (13 – 25)
24 (18 – 28)
22 (16 – 27)
Week 13
27 (23 – 32)
53 (49 – 64)
42 (27 – 53)
Mean body mass index (SD)
40.44 (9.48)
34.20 (5.05)
37.32 (8.11)
Marital status
Currently married
10 (67%)
4 (27%)
14 (47%)
Separated
0
1 (6.7%)
1 (3.3%)
Widowed
2 (13%)
0
2 (6.7%)
Divorced
2 (13%)
5 (33%)
7 (23%)
Never married
1 (6.7%)
5 (33%)
6 (20%)
Season of first dose
Fall
5 (33%)
5 (33%)
10 (33%)
Winter
3 (20%)
6 (40%)
9 (30%)
Spring
5 (33%)
1 (6.7%)
6 (20%)
Summer
2 (13%)
3 (20%)
5 (17%)
Mean vitals (SD)
Systolic blood pressure
134.73 (16.33)
131.13 (16.95)
132.93 (16.45)
Diastolic blood pressure
73.47 (10.99)
72.93 (10.79)
73.20 (10.70)
Heart rate
73.27 (12.67)
76.00 (12.86)
74.63 (12.62)
Mdn laboratory values (IQR)
HBA1C (mmol/mol)
Baseline
7.10 (6.30 – 7.50)
7.20 (6.20 – 7.80)
7.15 (6.30 – 7.70)
Week 13 ()
7.10 (6.30 – 7.70)
6.90 (6.00 – 8.60)
7.10 (6.20 – 7.70)
Glucose (mmol/L)
Baseline
120 (95 – 160)
142 (116 – 214)
134 (107 – 165)
Week 13
126 (98 – 138)
128 (100 – 195)
127 (100 – 160)
Creatinine (mg/dL)
Baseline
0.74 (0.66 – 0.90)
0.83 (0.70 – 0.88)
0.79 (0.69 – 0.88)
Week 13
0.78 (0.68 – 0.81)
0.80 (0.68 – 0.92)
0.79 (0.68 – 0.87)
Calcium (mg/dL)
Baseline
9.40 (9.30 – 9.60)
9.60 (9.40 – 9.90)
9.50 (9.30 – 9.70)
Week 13
9.50 (9.20 – 9.70)
9.70 (9.40 – 9.90)
9.50 (9.40 – 9.80)
Godin activity level
Insufficiently active
5 (33%)
6 (40%)
11 (37%)
Moderately active
3 (20%)
3 (20%)
6 (20%)
Active
7 (47%)
6 (40%)
13 (43%)
Mdn WRAT-4 Reading -score (IQR)
-1.00 (-1.20 to -0.33)
-0.93 (-1.20 to -0.20)
-0.97 (-1.20 to -0.33)
Mdn PHQ-9 score (IQR)
2 (1 – 4)
4 (3 – 7)
3 (2 – 5)
Mean CES-D score (SD)
7.13 (3.46)
9.73 (4.80)
8.43 (4.32)
Note: unless otherwise stated, valid for all demographics. SD = standard deviation of the mean. Mdn = median. IQR = interquartile range. ng/mL = nanograms per milliliter. PHQ-9 = Patient Health Questionnaire 9. CES-D = Center for Epidemiologic Studies Depression Scale.
