A qualitative study of knowledge, behaviour and attitudes regarding vitamin D acquisition among patients with photosensitivity disorders.

BACKGROUND: Cutaneous exposure to sunlight is a major source of vitamin D. Individuals with photosensitivity disorders have symptoms provoked by sunlight and may not achieve the brief sunlight exposures that convey vitamin D acquisition. OBJECTIVE: To explore knowledge, behaviour and attitudes towards vitamin D and its acquisition in patients with photosensitivity. METHODS: Patients (n = 19) diagnosed with solar urticaria, erythropoietic protoporphyria or polymorphic light eruption at a specialist photoinvestigation centre participated in semi-structured focus groups to discuss vitamin D knowledge, acquisition behaviours and attitudes towards vitamin D acquisition through sunlight and diet. Discussions were analysed by thematic analysis using MAXQDA11. RESULTS: Knowledge of vitamin D was variable. There was good awareness that sunlight exposure is an important source but knowledge of dietary sources was poor. Patients had little concern for their own vitamin D status prior to attending the photoinvestigation centre. Most patients avoided sunlight exposure, were unable to achieve the guidance on sun exposure for healthy individuals and were aware this could affect their vitamin D status. Use of oral vitamin D supplements was common, and all were willing to consider supplements if required. Patients recommended improving education of clinicians to increase patient awareness of vitamin D, CONCLUSIONS: More targeted guidance is required on acquisition of vitamin D for patients with photosensitivity, supported by increased patient and clinician education.

A qualitative study of the knowledge, behaviour and attitudes of patients with skin cancer regarding sunlight exposure and vitamin D.

BACKGROUND: Solar UVR is a major cause of skin cancer but also an important source of vitamin D (VitD), essential for musculoskeletal health. Conflicting public health messages may confuse patients with skin cancer prone to further skin cancer. OBJECTIVE: To explore the knowledge, behaviour and attitudes of patients with skin cancer to sunlight exposure and VitD sources. METHODS: Patients (n = 10) previously treated for multiple basal cell cancer in a hospital setting participated in focus group sessions with semi-structured discussions to explore: knowledge of VitD, sun-avoidance behaviour and attitude towards sunlight exposure messages. Thematic data analysis was performed using software programme MAXQDA11. RESULTS: Pre-existing knowledge of VitD was low. Most patients practised sun avoidance and were not inclined to increase exposure. Patients did not perceive VitD deficiency as a substantial risk to their own health, or a need to take VitD supplements. They aimed to increase VitD status through dietary intake, but knowledge of food VitD content was lacking. CONCLUSIONS: The patients with skin cancer, appropriate to their heightened skin cancer risk, appeared unlikely to increase their sun exposure to gain VitD. However, education is required regarding the generally low levels of VitD in foodstuffs, and the requirement for supplements/fortified foods if strict sun avoidance is employed.

Older Adults Who Spend More Time Outdoors in Summer and Have Higher Dietary Vitamin D Than Younger Adults Can Present at Least as High Vitamin D Status: A Pilot Study.

Vitamin D3 can be produced by exposing skin to UVB radiation or sourced through dietary products. It is often stated that vitamin D status declines in older adults, yet little is known about differences in current-day lifestyle and dietary behaviours influencing vitamin D outcomes in younger (18-40 years old) and older adults (65-89 years old). Our objectives were to perform a pilot study to compare sun exposure behaviours, i.e., time spent outdoors, holiday behaviour and use of sunscreen/clothing, and dietary vitamin D intake, in young and older adults in the UK, together with assessment of their vitamin D status. A total of 13 young and 11 older volunteers completed a four-page questionnaire to assess sun exposure and photoprotective behaviour and an eleven-page one-week vitamin D diet diary, alongside their plasma 25(OH)D measurement. It was found that the older group tended to spend more time outdoors during the working week in summer, to take more summer and winter holidays each year, take longer winter holidays and have similar sunscreen use when compared to younger adults. Older adults had a significantly higher daily dietary intake of vitamin D (4.0 µg) than young adults (2.4 µg). Mean winter 25(OH)D concentration was higher in older (56.9 nmol/L) than in young adults (43.2 nmol/L), but there was no statistical difference between the groups. Contrary to common assumptions, in this study, older adults had sun exposure and dietary behaviours conferring a vitamin D status at least as good as that of younger adults.

Fractional Sunburn Threshold UVR Doses Generate Equivalent Vitamin D and DNA Damage in Skin Types I-VI but with Epidermal DNA Damage Gradient Correlated to Skin Darkness.

Public health guidance recommends limiting sun exposure to sub-sunburn levels, but it is unknown whether these can gain vitamin D (for musculoskeletal health) while avoiding epidermal DNA damage (initiates skin cancer). Well-characterized healthy humans of all skin types (I-VI, lightest to darkest skin) were exposed to a low-dose series of solar simulated UVR of 20%-80% their individual sunburn threshold dose (minimal erythema dose). Significant UVR dose responses were seen for serum 25-hydroxyvitamin D and whole epidermal cyclobutane pyrimidine dimers (CPDs), with as little as 0.2 minimal erythema dose concurrently producing 25-hydroxyvitamin D and CPD. Fractional MEDs generated equivalent levels of whole epidermal CPD and 25-hydroxyvitamin D across all skin types. Crucially, we showed an epidermal gradient of CPD formation strongly correlated with skin darkness (r = 0.74, P < 0.0001), which reflected melanin content and showed increasing protection across the skin types, ranging from darkest skin, where high CPD levels occurred superficially, with none in the germinative basal layer, to lightest skin, where CPD levels were induced evenly across the epidermal depth. People with darker skin can be encouraged to use sub-sunburn UVR-exposure to enhance their vitamin D. In people with lighter skin, basal cell damage occurs concurrent with vitamin D synthesis at exquisitely low UVR levels, providing an explanation for their high skin cancer incidence; greater caution is required.

Green tea catechins and their metabolites in human skin before and after exposure to ultraviolet radiation.

Dietary flavonoids may protect against sunburn inflammation in skin. Preliminary reports using less complete analysis suggest that certain catechins and their metabolites are found in skin biopsies and blister fluid after consumption of green tea; however, it is not known if they are affected by solar-simulated ultraviolet radiation (UVR) or whether conjugated forms, with consequently altered bioactivity, are present. The present study tested the hypothesis that UVR affects the catechin levels in the skin of healthy volunteers after consumption of green tea and how catechins in the plasma are related to their presence in skin tissue samples. In an open oral intervention study, 11 subjects consumed green tea and vitamin C supplements daily for 3months. Presupplementation and postsupplementation plasma samples, suction blister fluid and skin biopsies were collected; the latter two samples were collected both before and after UVR. A sensitive high-performance liquid chromatography/mass spectrometric assay was used to measure the intact catechin metabolites, conjugates and free forms. Seven green tea catechins and their corresponding metabolites were identified postsupplementation in skin biopsies, 20 in blister fluid and 26 in plasma, with 15 green tea catechin metabolites present in both blister fluid and plasma. The valerolactone, O-methyl-M4-O-sulfate, a gut microbiota metabolite of catechins, was significantly increased 1.6-fold by UVR in blister fluid samples. In conclusion, there were some common catechin metabolites in the plasma and blister fluid, and the concentration was always higher in plasma. The results suggest that green tea catechins and metabolites are bioavailable in skin and provide a novel link between catechin metabolites derived from the skin and gut microbiota.