Adherence and barriers to the vitamin D and calcium supplement recommendation at Danish nursing homes: A cross-sectional study

Background: Vitamin D and calcium supplements are recommended in Denmark to all nursing home residents due to the supplement’s preventive effect on osteoporosis and bone fractures, however the implementation of the recommendation as well as knowledge of it among nursing home staff are currently unknown.
Objectives: The objectives of this study were to investigate adherence, knowledge, attitudes, and potential barriers to The Danish Health Authority recommendation of providing all nursing home residents daily supplements with 20 µg vitamin D and 800-1000 mg calcium.
Methods: This was a cross-sectional study conducted in May-June 2020 among 50 randomly selected nursing homes widely distributed in Denmark. An electronic 20-item survey was sent by e-mail to each nursing home. Questions included degree of adherence to the recommendation at each nursing home estimated as percentage of residents receiving both supplements ≥5 days per week. Moreover, questions included respondent’s knowledge and attitudes towards the recommendation, and experienced barriers in relation to adherence.
Results: Respondents from 41 nursing homes answered the questionnaire, and these were mainly nurses (63%) or nursing home leaders (20%). Low adherence (≤40% of residents receiving both supplements) was reported at 35% of nursing homes, and only 8 % of the nursing homes had a high adherence (>80% of residents receiving both supplements). Most respondents (88%) had knowledge of the recommendation and 62% rated importance of increased adherence at their nursing home as 4-5 on a 1-5 scale. Common explanations of low adherence to the recommendation were a lack of prescription by the general practitioner (60%), resident-refusal to eat the tablets (43%) and chewing-swallowing difficulties among residents (40%).
Conclusions: The recommendation of daily vitamin D and calcium supplements to Danish nursing home residents is poorly implemented even though knowledge of the recommendation is relatively high. Barriers relate to an ambiguity of responsibility between the general practitioners and the nursing home staff, as well as the high number of tablets to be consumed in total by the residents. These barriers must be targeted to improve adherence in this vulnerable group of institutionalized older adults.