Vitamin D Status in Patients With Chronic Plaque Psoriasis

P. Gisondi; M. Rossini; A. Di Cesare; L. Idolazzi; S. Farina, G. Beltrami; K. Peris; G. Girolomoni


The British Journal of Dermatology. 2012;166(3):505-510. 

In This Article


The characteristics of the study population are reported in Table 1. Patients with psoriasis were younger than patients with RA; they were more frequently smokers and alcohol consumers and had a greater BMI compared with those with RA and with healthy controls. Levels of 25(OH)D were significantly lower in patients with psoriasis compared with healthy controls (P < 0·01), whereas there was no difference between patients with psoriasis and those with RA (P < 0·45) (Fig. 1). Mean serum levels of 25(OH)D were 19·3 ± 10·8 ng mL−1 in female patients with psoriasis and 21·2 ± 11·5 ng mL−1 in male patients (P < 0·3). There were no differences in PTH and calcium serum levels among the three groups (P < 0·09 and P < 0·2, respectively). There were no differences between the three groups in the prevalence of those exposed to sun > 30 min per day from March to September (P < 0·4).

Figure 1.

Serum levels of 25-hydroxyvitamin D [25(OH)D] in healthy controls (white bar), patients with psoriasis (grey bar) and patients with rheumatoid arthritis (RA) (dashed bar). *P < 0·001 vs. healthy controls.

The prevalence of 25(OH)D deficiency in the three groups is reported in Figure 2. The prevalence of patients with 25(OH)D deficiency was much higher in those with psoriasis compared with patients with RA (P < 0·01) and healthy controls (P < 0·001) (Fig. 2b). As expected, serum 25(OH)D levels varied significantly according to the season during which the blood sampling was taken. In particular, in those with psoriasis, serum 25(OH)D levels (ng mL−1) were 19·1 ± 7·6 (mean ± SD) in spring, 27 ± 14·5 in summer, 20·1 ± 12·6 in autumn and 16 ± 10·5 in winter (P < 0·01). The proportion of psoriatic patients with vitamin D deficiency was higher during the winter, i.e. 81% (17 of 21 patients) compared with spring, i.e. 60% (39 of 65 patients), summer 37% (11 of 30 patients) and autumn 58% (14 of 24), P < 0·01 (Fig. 2a). Similarly, the prevalence of vitamin D deficiency in winter increased to 41% in patients with RA and to 30% in healthy controls (P < 0·001). Mean serum levels of 25(OH)D in patients with psoriasis (n = 86) were similar to those in patients with psoriasis and concomitant PsA (n = 59) (21·3 ± 11·6 vs. 19·7 ± 10·8 ng mL−1; P < 0·4) as well as the prevalence of those with vitamin D deficiency (54% vs. 63%; P < 0·2). The clinical and biochemical data of patients with psoriasis stratified by vitamin D deficiency (n = 81) are reported in Table 2. As expected, serum 25(OH)D levels were significantly lower in patients with deficiency compared with those without deficiency (14·9 ± 3·1 vs. 46·5 ± 28·1; P < 0·0001). In contrast, there were no differences in age, sex, smoking status, BMI, prevalence of diabetes or PsA, severity of psoriasis and serum levels of CRP, PTH and calcium between the two groups. In particular, there was no significant linear correlation between PASI score and 25(OH)D levels. In the multivariate regression analysis, vitamin D deficiency was associated with the presence of psoriasis [odds ratio (OR) 2·5; 95% confidence interval (CI) 1·18–4·89; P < 0·01] independently of age, sex, BMI, calcium, PTH levels and season during which the blood sample was taken (Table 3). Moreover, 25(OH)D deficiency was directly associated with the PTH serum levels (OR 1·22; 95% CI 1·08–1·34; P < 0·04).

Figure 2.

(a) Proportion of patients with psoriasis with vitamin D deficiency in different seasons. *P < 0·01 vs. autumn, spring and summer. (b) Proportion of subjects with vitamin D deficiency *P < 0·001 vs. healthy controls and patients with rheumatoid arthritis (RA). 25(OH)D, 25-hydroxyvitamin D.


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.
Post as: