Patient satisfaction and adherence to vitamin D supplementation: results from a nationwide survey in Italy.

OBJECTIVE

The objective of the present study was to evaluate patient satisfaction and adherence to different vitamin D formulations and dosing regimens in a large Italian cohort of patients treated for osteoporosis or vitamin D deficiency.

METHODS

We did a cross-sectional study; a questionnaire (FEDIOS Survey, version 3.2) was administered across multiple centers under FEDIOS patronage. Questions assessed socio-demographic data, vitamin D treatment characteristics, perceived convenience, tolerability, adherence (Morisky scale), and overall satisfaction.

RESULTS

A total of 658 respondents (mean age 65.5±13.1 years; 86% women) completed the questionnaire. Most participants had a high school diploma (38%), and 96% were currently taking vitamin D, predominantly as liquid formulations (bottles 67%, ampoules 23%). The most frequent dosing was monthly (41%), followed by weekly (37%) and daily (19%). Laboratory confirmation of deficiency was obtained in 83% of cases; 49% were treated for osteoporosis. Only 14% reported difficulties with intake, most commonly problems opening ampoules (36%) or forgetting doses (33%). On a 7-point Likert scale, mean satisfaction scores were 5.74±1.08 for overall treatment satisfaction and 5.81±1.11 for willingness to continue treatment. The Morisky adherence score averaged 1.44 to 1.55 for most formulations, indicating moderate-to-high adherence without significant inter-group differences (p=0.78). However, monthly regimens, especially ampoules and bottles, were associated with significantly higher satisfaction for dosing frequency and continuation intention (p=0.017 and 0.018, Δ≈+9%). Global satisfaction was highest for monthly ampoules (6.08±0.82) and monthly tablets (6.18±0.91), and lowest for daily tablets (5.69±1.01).

CONCLUSIONS

In summary, vitamin D supplementation was generally well accepted among Italian patients, with a preference for monthly liquid formulations, perceived as more convenient and easier to manage. Simplified dosing schedules appear to enhance satisfaction and support sustained adherence.