Table II. Studies examining the efficacy of vitamin D supplementation in psoriasis and psoriatic arthritis.
| Study | Disease | Region | Study Design | Length | Number of Patients | Vitamin D3 Form Dose (microgram/day) | Results |
|---|---|---|---|---|---|---|---|
| Perez et al. 1996 | Psoriasis | United States | Prospective, uncontrolled | 6 months to 3 years | 85 | 1,25-dihydroxy Started at 0.5 and increased by 0.5 every 2 weeks as long as 24 hour urinary calcium concentrations remained normal | 26.5% had complete improvement 36.2% had moderate improvement 25.3% had slight improvement Mean PASI 18.4 ± 1.0 at baseline, 9.7 ± 0.8 at 6 months, 7.8 ± 1.3 at 24 months |
| Siddiqui et al. 1990 | Psoriasis | Saudi Arabia | Prospective, randomized, double-blind placebo controlled | 3 months | 41 | 1-hydroxy 1.0 | 9/20 (45%) on Vit D showed slight improvement vs 8/21 (38%) on placebo showed slight improvement, no statistically significant difference |
| Morimoto et al. 1986 | Psoriasis | Japan | Prospective, uncontrolled | 6 months | 17 | 1-hydroxy 1.0 | 76% of patients displayed moderate or greater improvement after 2.7 ± 0.6 months |
| Smith et al. 1988 | Psoriasis | United States | Prospective, uncontrolled | 6 to 12 months | 14 | 1,25-dihydroxy 0.5 to 2.0 | 7/14 (50%) improved greater than 75% 3/14 (21%) improved 25-50% 4/14 (29%) patient improved 0-25% |
| Finamor et al. 2013 | Psoriasis | Brazil | Prospective, uncontrolled | 6 months | 9 | cholecalciferol 875.0 | There was a statistically significant improvement in PASI scores from baseline to 6 months (p<0.01); PASI scores inversely correlated with serum 25-hydroxyvitamin D3 levels (p<0.001) |
| El-Azhary et al. 1993 | Psoriasis | United States | Prospective, uncontrolled | 6 months | 8 | 1,25-dihydroxy 0.5 to 2.0 | 1/8 (12.5%) improved markedly 1/8 (12.5%) improved moderately 6/8 (75%) with no or mild improvement |
| Takamoto et al. 1986 | Psoriasis | Japan | Prospective, uncontrolled | 6 months | 7 | 1-hydroxy 1.0 | 2/7 (29%) showed complete remission 2/7 (29%) showed marked improvement 3/7 (43%) showed no improvement |
| Gaal et al. 2009 | Psoriatic arthritis | Hungary | Prospective, uncontrolled | 6 months | 19 | 1-hydroxy 0.5 | DAS28 score decreased from a mean of 45 ± 11 to 29 ± 10 |
| Huckins et al. 1990 | Psoriatic arthritis | United States | Prospective, uncontrolled | 6 months | 10 | 1,25-dihydroxy 2.0 | 4/10 (40%) improved 50% or more in tender joint count; 3/10 (30%) improved 25-50% in the tender joint count. 2/10 (20%) unable to receive therapeutic doses because of hypercalciuria. |