Table 2

Statistical analysis of Study 2 scores of wellbeing (Winter 2002–2003).


Intent-to-treat analysis
Per-protocol analysis


Dose of Vitamin D
N
Age

N

mcg/day (IU/day)
Total in group, (% female)
yr (SD)
25(OH)D nmol/L (SD)
December
2002 Score
(out of 16)
February
2003
Score
(out of 16)
Total in group,
(% female)
December
2002 Score
(out of 16)
February
2003 Score
(out of 16)

CONTINUERS FROM STUDY 1 (on Vit D since previous year)
15 (600)
22 (77%)
54 (14)
69 (26)
7.2 (4.5)
4.4 (3.4)
15 (73%)
6.9 (4.8)
4.4 (3.4) b
100 (4000)
24 (84%)
56 (9)
126 (45) a
4.4 (4.4) a
4.0 (3.7)
16 (88%)
4.6 (4.6)
4.0 (3.7)
NEW PATIENTS FOR STUDY 2
15 (600)
33 (68%)
48 (13)
39 (9)
8.0 (5.2)
5.4 (4.3)
25 (64%)
8.7 (5.5)
5.4 (4.3) b
100 (4000)
33 (85%)
50 (14)
39 (9)
8.4 (5.5)
3.9 (3.6) c
26 (89%)
8.1 (5.6)
3.9 (3.6) bc

a Different from 15 mcg (600 IU)/day group (the value above the mean marked by this footnote) by t-test p < 0.04; lower (better) than in the 600 IU/day group by Mann-Whitney p = 0.039.

b Paired t-test, December score vs February Score (the value to the left of the mean marked by this footnote) p < 0.012; also significant by the non-parametric equivalent to paired t-test, the Wilcoxan test, p < 0.012.

c For New patients, low vs high dose group, 2-tail unpaired t test p = 0.188; Mann-Whitney p = 0.183; i.e. not significantly different.

Vieth et al. Nutrition Journal 2004 3:8   doi:10.1186/1475-2891-3-8