Target the message: a qualitative study exploring knowledge and cultural attitudes to sunlight and vitamin D in Greater Manchester, U.K.

Dear Editor, Vitamin D is vital for musculoskeletal health and has been associated with protection against several internal cancers and autoimmune diseases.1,2 Skin synthesis following exposure to ultraviolet radiation (UVR) in sunlight is the major source of the vitamin, with diet providing only small amounts.3 Skin synthesis requires sunlight exposure containing sufficient UVB to initiate vitamin D synthesis, which precludes the winter months at mid‐to‐high latitudes, including the U.K.3,4 Without continuous supplementation, maintaining vitamin D sufficiency, defined as circulating 25‐hydroxyvitamin D ≥ 50 nmol L−1 (20 ng mL−1),2 is most efficiently achieved through casual sunlight exposure to unprotected skin. This contrasts with public health messages from the past 20 years advocating sun protection to reduce skin cancer risk, and to some cultural practices, exacerbated in those with naturally pigmented skin, as melanin absorbs a proportion of the UVR.5,6 Studies in Greater Manchester, U.K. (53·5°N)5,7,8,9 involving white and South Asian adults showed sunlight exposure to be the primary means of acquiring vitamin D, with diet being a low source. A seasonal 25‐hydroxyvitamin D cycle was observed in both groups, with lower amplitude in South Asian adults, of whom 93% had levels < 50 nmol L−1 throughout the year.9 Vitamin D guidance states that ‘most people should be able to make enough from short, casual exposure like you might get just by going about your daily life’.10 Thus we undertook a qualitative focus group study involving healthy white and South Asian volunteers to explore knowledge and attitudes towards vitamin D and sunlight exposure/protection behaviour. This methodology can effectively explore views and beliefs to understand and explain factors influencing individuals’ attitudes and behaviours.11 Casual exposure was quantified as ~15 min to the face, arms and legs, most days of the week during summer for white individuals,7 and 30–40 min for South Asians.6 The University of Manchester Research Ethics Committee granted ethical approval (reference 14133). Study documentation was made available in English and Urdu, and all volunteers provided written informed consent. Three focus groups were held from May to July 2014, defined by ethnicity and primary language (Table 1), conducted by a multilingual researcher experienced in focus group facilitation and supported by an English‐speaking vitamin D expert. All volunteers were recruited from the Longsight area of Greater Manchester, avoiding confounding by socioeconomic status. A brief introduction was followed by open‐ended questions, including general questions about sunlight and vitamin D and more specific queries about personal sun exposure. There was ample interaction between group members, and discussion was encouraged to continue until no new information was forthcoming. Audio recordings were translated where required, and transcribed into Microsoft Word. Transcripts were coded using MAXQDA 11 (qualitative data analysis software; http://www.maxqda.com/) then exported to matrices for analysis by systematic text condensation. Details of the focus groups and volunteers Details of the focus groups and volunteers For South Asian adults in Longsight, living in a strongly traditional community, primary language did not seem to indicate the degree of cultural assimilation, although no volunteers had fully adopted a Western lifestyle (indicated by dress, language and cultural references). All but one of the South Asian volunteers were female, who usually control the family diet and may influence the health behaviour of family members. Most were restricted in dress by cultural traditions, with the results reflecting the cultural contrast between this group and the white participants (Table 2). Illustrative responses from focus group participants on the main topics of discussion GP, general practitioner. Illustrative responses from focus group participants on the main topics of discussion GP, general practitioner. The level of awareness of vitamin D and its relationship to sunlight exposure was similar in the two South Asian groups but contrasted with that of the white group. South Asians were much more knowledgeable, with the majority aware that vitamin D was important for bone health and could be obtained from sunlight exposure. The white adults had a substantial lack of knowledge, with most unaware of vitamin D sources or its association with sunlight exposure. The greater knowledge of the South Asians appeared to be due primarily to experience with symptoms of poor bone health, either directly or through a family member or community acquaintance, resulting in a general practitioner visit and vitamin D blood test. Despite this greater knowledge, use of vitamin D supplements by the wider South Asian population in Greater Manchester is extremely low, and levels of sunlight exposure are less than those of white adults in the same location.9 However, for South Asian participants taking supplements, this was their preferred method of vitamin D acquisition, while the white group was generally averse to regular supplement taking. Thus, for South Asians, communication of advice may be inadequate rather than there being an unwillingness to take supplements. National guidance to practise brief sunlight exposure for vitamin D acquisition was well received by the white group, but was associated more with enjoyment of spending time outdoors in sunlight than with vitamin D. In contrast, some South Asians practised sunlight exposure specifically for vitamin D acquisition. However, there was misunderstanding regarding the need for direct sunlight exposure to unprotected skin, with several participants incorrectly believing that exposure indoors through window glass was sufficient. Thus more explicit guidance is indicated; in addition to advice on amounts of sunlight exposure there needs to be education about how vitamin D is acquired. The white participants were confused by mixed messages regarding sunlight exposure (risk/benefit) and frequently used sunscreen as they correctly associated sunburn and excessive sunlight exposure with risk of skin cancer. Furthermore, poor knowledge of dietary vitamin D sources meant that many participants regarded a ‘balanced diet’ as being adequate. Few qualitative studies have explored sunlight exposure and vitamin D in healthy adults. Studies from Australia and the U.K. report lack of vitamin D knowledge and confusion surrounding contradictory sunlight exposure messages.12,13,14 Clearly, risk–benefit balance and nutritional messages require better communication.15 Our three focus groups felt that better information provided in a variety of formats would help raise awareness and let individuals make appropriate choices of their preferred source of vitamin D. Public health messages and educational campaigns should include culturally appropriate advice to better target the needs of different population sectors. We thank Caroline Lalley for transcription assistance. Funding sources: This study was funded by the U.K. Department of Health Policy Research Programme 024/0050. Conflicts of interest: none declared.