Patients` Adherence and Satisfaction from Daily Versus Monthly Vitamin D Supplementation: Results from a Dedicated Bone Clinic

Introduction:
Monthly vitamin D supplementation is not inferior to daily regarding target vitamin D levels and might increase adherence. Patients` adherence and satisfaction with daily versus monthly vitamin D supplementation have been hardly investigated.

Aim:
To evaluate patients with osteopenia/osteoporosis regarding adherence and satisfaction from vitamin D supplementation after switching from monthly to daily (MtD) dosing and vice versa (DtM).

Methods:
Ambulatory osteopenic/osteoporotic patients were asked to switch their vitamin D supplementation from MtD and vice versa. Total monthly dose remained unchanged. Patients answered questionnaires regarding socio-demographics, medical status, compliance with vitamin D dosing (MMAS-8), satisfaction with regimen and physical functional status (OPAQ-15) at baseline and 6 months after switching.

Results:
Among 72 patients recruited (71.5±7.4Y, 91.7%F), 52(72.2%) were switched from DtM treatment, 20(27.7%) from MtD. Baseline vitamin D level was 86.1±17.2 nmol/l. Both groups expressed good baseline compliance (MMAS-8 score ≥8; 98.1%) and good baseline satisfaction (∼75%) with vitamin D regimen. Baseline physical status was good in 63.9% and moderate in 33.3%. After switching, satisfaction level, adherence to vitamin D regimen, vitamin D level and functional capacity remained unchanged. 68.8% of MtD and 52% of DtM patients wanted to remain on the current regimen. Among patients who experienced both regimens, 56.1% preferred the daily one.

Conclusions:
Patients with osteopenia/osteoporosis had good adherence to monthly/daily vitamin D regimens and expressed high level of satisfaction with them. All parameters remained stable after switching regimens. Large-scale studies are needed to evaluate the effects of various dosing regimens on patients` satisfaction and adherence.