11 Gaps in the evidence
The Public Health Advisory Committee (PHAC) identified a number of gaps in the evidence related to the programmes under examination, based on an assessment of the evidence, expert and stakeholder comment. These gaps are set out below.
1. There is a lack of good quality interventions aiming to increase Vitamin D supplement use among specific population groups in England.
2. There is a lack of good quality evidence on the relative impact of the following on the uptake of vitamin D supplements among specific population groups: awareness-raising activities, health professional training and supplement provision.
3. There is a lack of good quality evidence on whether making a free or low cost vitamin D‑only supplement available affects uptake among specific population groups.
4. There is a lack of evidence on whether the following affect the effectiveness of interventions to increase vitamin D supplement use among specific population groups: sexual orientation, disability, religion, place of residence, occupation, education, socioeconomic position or a sense of community (or 'social capital').
5. There is a lack of evidence on what strategies may encourage people to take a vitamin D supplement on a regular basis.
6. There is a lack of evidence on whether health professional training leads to more effective interventions to improve uptake of vitamin D supplements among specific population groups.
(Source: review 1 and review 2)
The Committee made 5 recommendations for research into areas that it believes will be a priority for developing future guidelines. These are listed in recommendations for research.