Table 1 Overview of RCTs that examined the effect of vitamin D supplementation on depression

Lansdowne et al., 1998 [68]

44 healthy adults, age 18–43 yrs., 77 % female.

No

No

400 or 800 IU/day vitD₃ vs. placebo for 5 days in late winter.

Positive and negative affect (PANAS).

Improved positive affect, possibly reduced negative affect in both vitD groups.

Jorde et al., 2008 [69]

441 overweight/obese outpatients or community dwellers, age 21–70 yrs., 64 % female.

No

No

20,000 or 40,000 IU/week vitD₃ vs. placebo for 1 yr.

Depressive symptoms (BDI).

Lower depression scores in both vitD groups. Effect more pronounced in persons with higher baseline depression scores.

Sanders et al., 2011 [70]

2012 community dwelling women, age 70+ yrs.

No

No

500,000 IU vitD₃ vs. placebo once every autumn/winter for 3–5 yrs.

Mental well-being (GHQ, SF-12, WHO Well-Being index.

NS.

Dean et al., 2011 [71]

128 healthy adults, age 18–30 yrs., 57 % female.

No

No

5000 IU/day vitD₃ vs. placebo for 6 weeks.

Depressive symptoms (BDI).

NS.

Bertone-Johnson et al., 2012 [72]

2263 post-menopausal women, age 50–79 yrs.

No

No

400 IU/day vitD₃ + 1000 mg/day calcium vs. placebo for 2 yrs.

Depressive symptoms, MDD (Burnam scale, antidepressant use).

NS.

Yalamanchiliet al., 2012 [73]

412 post-menopausal women, age 65–77 yrs.

No

No

Calcitriol 0.25 g twice daily vs. placebo + estrogens vs. placebo for 3 yrs.

Depressive symptoms (GDS).

NS.

Khoraminya et al., 2012 [28]

40 outpatients with MDD, age 18–65 yrs., 85 % female.

No

Yes: MDD diagnosis.

1500 IU/day vitD₃ + 20 mg fluoxetine vs. fluoxetine alone for 8 weeks.

Depression severity (HDRS), depressive symptoms (BDI).

Vitamin D + fluoxetine superior to fluoxetine alone in reducing depressive symptoms.

Kjærgaard et al., 2012 [29]

230 community dwellers, age 30–75 yrs., 56 % female.

Yes: 25(OH)D <55 nmol/L.

No

40,000 IU/week vitD₃ vs placebo for 6 months.

Depressive symptoms (BDI, HADS, MADRS).

NS.

Mozaffari- Khosravi et al., 2013 [30]

109 psychiatric outpatients, age 20–60 yrs., 72 % female.

Yes: 25(OH)D < 40 nmol/L.

Yes: BDI score ≥17.

Single dose of 150,000 or 300,000 IU vitD₃ vs. no injection.

Depressive symptoms after 3 months (BDI).

Reduced depressive symptoms in 300,000 IU group.