25-Hydroxyvitamin-D3 serum modulation after use of sunbeds compliant with European Union standards: A randomized open observational controlled trial

Trends of serum 25(OH) vitamin D and association with cardiovascular disease and all-cause mortality: from NHANES survey cycles 2001-2018

Background

The focus of this survey is on survey data for adults aged 20 and above, covering nine survey cycles from 2001 to 2018. Additionally, the present study explored the correlation between vitamin D concentrations and both cardiovascular disease (CVD) and all-cause mortality.

Objective

The objectives of this study were to evaluate the trend of changes in the serum 25(OH)D concentration changes in US adults during the survey period, the prevalence of vitamin D deficiency, and the current status of vitamin D dietary intake and supplementation.

Methods

In-home health interviews were performed using meticulously designed questionnaires that gathered information on demographic details, socioeconomic conditions, dietary patterns, and overall health status. Health assessments were conducted in specially designed mobile centers.

Results

Survey data from 2001 to 2018 revealed a rise in serum 25(OH)D levels, from a weighted mean (95% CI) of 65.6 (63.8-67.4) nmol/L during 2001-2002 to 73.5 (70.4-76.5) nmol/L during 2017-2018, among US adults, while overall vitamin D deficiency rates remained stable (p = 0.152). Notably, in adults aged 20-39, 25(OH)D levels decreased (p = 0.002 for trend), and 25(OH)D deficiency increased (p = 0.003 for trend), especially among those with low incomes (deficiency >30%). Upon multivariable adjustment, an L-shaped relationship was found between serum 25(OH)D concentrations and both CVD and all-cause mortality (p < 0.001 for nonlinearity), as corroborated by sensitivity analyses.

Conclusion

From 2001 to 2018, US adults experienced a significant increase in their serum 25(OH) D concentration. However, subgroups of individuals, including young adults and individuals with lower socioeconomic status, exhibited a heightened risk of 25(OH)D deficiency. Furthermore, an L-shaped relationship was found between 25(OH)D concentration and both all-cause and CVD mortality among US adults.

Serum levels of folate, 25-hydroxyvitamin D3 and cobalamin during UVB phototherapy: findings in a large prospective trial

Background

Narrowband UVB phototherapy (NB‐UVB) is a mainstay in the treatment of numerous inflammatory dermatoses. Whereas, a wealth of studies has shown that NB‐UVB treatment increases 25‐hydroxyvitamin D3 (25(OH)D) levels, only sparse and controversial data exist on its effect on serum folate and cobalamin.

Objectives

To determine whether exposure to NB‐UVB alters serum folate or cobalamin levels.

Methods

A single‐centre, prospective, open observational study on 101 patients subjected to NB‐UVB phototherapy between late fall and early spring. Serum folate, 25(OH)D and cobalamin levels were measured after 0, 12, 24 and 36 NB‐UVB exposures.

Results

After 12 NB‐UVB exposures a significant decrease of mean serum folate (−1.0 nmol/L; P = 0.03) and cobalamin (−14.5 pmol/L, P = 0.03) levels was observed whereas serum levels of 25(OH)D showed a significant increase (35.4 nmol/L, P < 0.0001).

Conclusions

A standard course of NB‐UVB induces a small but significant decrease of serum folate and cobalamin levels.

Overview on vitamin D and sunbed use

Vitamin D seems to be associated with a protective effect in a vast range of diseases, including cardiovascular, autoimmune and oncologic conditions. Since ultraviolet (UV) B light is the most important prerequisite for the cutaneous synthesis of vitamin D, sunbeds are able to increase serum vitamin D levels, although only transiently in most cases. In this scenario, the artificial tanning industry relentlessly tries to promote the use of sunbeds as a 'safe' therapeutic measure to achieve an adequate serum vitamin D status. The World Health Organization classified UV-emitting tanning devices, as well as the whole UV spectrum, as group-1 carcinogens, as they significantly increase the risk of melanoma and non-melanoma skin cancer. In case of vitamin D deficiency or insufficiency, the current risk-benefit ratio is therefore in favour of vitamin D supplementation instead of sunbed use. Artificial tanning devices should never be considered as an option to achieve an appropriate vitamin D status. Their supposedly beneficial effects, vastly publicised by the artificial tanning industry, are not worth the carcinogenic risk associated with sunbed use.

Feasibility of vitamin D supplementation interventions to mitigate HIV pre-exposure prophylaxis-related bone mineral density loss: a cross-sectional survey

BACKGROUND

Daily tenofovir disoproxil fumarate (TDF)/emtricitabine as HIV pre-exposure prophylaxis (PrEP) causes subclinical decreases in bone mineral density (BMD). We surveyed PrEP users to assess feasibility for a clinical trial of vitamin D supplementation to mitigate TDF-induced BMD loss.

METHODS

We recruited participants using or starting PrEP in Toronto and Vancouver. The primary objective was to assess the acceptability of daily or weekly vitamin D supplementation. We also assessed the acceptability of calcium supplementation, existing use of non-pharmacological bone health interventions, prevalence of osteoporosis risk factors, and bone health knowledge (Osteoporosis Knowledge Test, OKT).

RESULTS

Of 161 participants, 72.1% were current PrEP users, 18.0% were starting PrEP, and 9.9% did not indicate their PrEP status. All identified as males, 88.8% as gays, and 67.1% as Whites. Median (IQR) age was 32.0 (29.0, 40.0) years, and 62.1% reported family income $$60,000/year. Among those not already using the interventions, willingness to supplement with daily vitamin D, weekly vitamin D, or daily calcium was very high at 90.9%, 96.4%, and 93.0 %, respectively. Only 31.0% reported adequate dietary calcium intake, while 42.9% reported $1 osteoporosis risk factor (most commonly, alcohol and smoking). Overall bone health knowledge was low, as median (IQR) OKT score was 16/32. In post hoc comparisons, current PrEP users may have been more likely than new PrEP users to engage in bone loading exercise (Bone-specific Physical Activity Questionnaire score=12.5 vs 3.6, P=0.001) and have greater bone health knowledge (OKT=17 vs 14, P=0.08), but they had similar levels of current vitamin D supplementation (37.4% vs 21.4%, P=0.11), calcium supplementation (11.2% vs 13.8%, P=0.70), and adequate dietary calcium intake (32.7% vs 25.0%, P=0.43).

DISCUSSION

The high acceptability of vitamin D and calcium supplementation in this cohort suggests that enrollment into a clinical trial of such interventions to mitigate PrEP-induced BMD loss is feasible.