Insufficient Sun Exposure Has Become a Real Public Health Problem

Epidemiologic Data of Vitamin D Deficiency and Its Implication in Cardio-Cerebrovascular Risk in a Southern Italian Population

Background

Vitamin D (25(OH)D) deficiency is a prevalent condition worldwide. However, the highest prevalence rates of 25(OH)D deficiency have been attributed to regions with higher latitude. A close association between 25(OH)D and cardio-cerebrovascular (CCV) risk factors and major health problems has been identified.

Aim

To establish the prevalence of 25(OH)D deficiency and to investigate the relationship between 25(OH)D levels and CCV risk factors (blood cholesterol, triglycerides, glucose concentrations, body mass index, and systolic and diastolic blood pressure) in a cohort representative of Southern Italy.

Methods

The prevalence of 25(OH)D levels was evaluated in 1200 subjects aged 25-74 years (600 males and 600 females), enrolled in the "VIP" (from Italian for Irno Valley Prevention) Project, whereas multiple linear regression analysis was used to determine the relationship between 25(OH)D levels and CCV risk factors.

Results

Only 13.3% of females and 11.1% of males showed adequate serum concentrations of 25(OH)D (≥30 ng/ml), while 59.3% of females and 55.1% of males showed 25(OH)D deficient levels (<20 ng/ml). We observed an independent association between 25(OH)D concentrations and metabolic syndrome score, LDL cholesterol, HDL cholesterol, and corrected QT (cQT).

Conclusions

We report a high prevalence of 25(OH)D deficiency across the largest Italian adult population studied so far and, in particular, the first across Southern Italy; furthermore, we provide data on the association between 25(OH)D deficiency and higher CCV risk factors.

Ultraviolet A radiation and COVID-19 deaths in the USA with replication studies in England and Italy

Background

Understanding factors impacting deaths from COVID‐19 is of the highest priority. Seasonal variation in environmental meteorological conditions affects the incidence of many infectious diseases and may also affect COVID‐19. Ultraviolet (UV) A (UVA) radiation induces release of cutaneous photolabile nitric oxide (NO) impacting the cardiovascular system and metabolic syndrome, both COVID‐19 risk factors. NO also inhibits the replication of SARS‐CoV2.

Objectives

To investigate the relationship between ambient UVA radiation and COVID‐19 deaths.

Methods

COVID‐19 deaths at the county level, across the USA, were modelled in a zero‐inflated negative‐binomial model with a random effect for states adjusting for confounding by demographic, socioeconomic and long‐term environmental variables. Only those areas where UVB was too low to induce significant cutaneous vitamin D3 synthesis were modelled. We used satellite‐derived estimates of UVA, UVB and temperature and relative humidity. Replication models were undertaken using comparable data for England and Italy.

Results

The mortality rate ratio (MRR) in the USA falls by 29% [95% confidence interval (CI) 40% to 15%) per 100 kJ m^–2 increase in mean daily UVA. We replicated this in independent studies in Italy and England and estimate a pooled decline in MRR of 32% (95% CI 48% to 12%) per 100 kJ m^–2 across the three studies.

Conclusions

Our analysis suggests that higher ambient UVA exposure is associated with lower COVID‐19‐specific mortality. Further research on the mechanism may indicate novel treatments. Optimized UVA exposure may have population health benefits.

Vitamin D composition of Australian foods

Australia needs accurate vitamin D food composition data to support public health initiatives. Previously, limitations in analytical methodology have precluded development of a comprehensive database. We used liquid chromatography with triple quadrupole mass spectrometry (LC-QQQ) to analyse 149 composite samples representing 98 foods (primary samples n = 896) in duplicate for vitamin D₃, 25-hydroxyvitamin D₃ (25(OH)D₃), vitamin D₂, 25(OH)D₂. The greatest concentrations of vitamin D₃ were found in canned salmon and a malted chocolate drink powder (fortified); chicken eggs and chicken leg meat contained the most 25(OH)D₃. Margarine (fortified) and chocolate contained the greatest concentrations of vitamin D₂, with smaller amounts found in various meat products. 25(OH)D₂ was detected in various foods, including meats, and was quantitated in lamb liver. These data advance knowledge of dietary vitamin D in Australia and highlight the importance of analysis of these four forms of vitamin D to accurately represent the vitamin D content of food.

Risk Factors Associated with Vitamin D Status among Older Puerto Rican Adults

BACKGROUND

Vitamin D deficiency has been associated with health problems globally, but there is limited information on vitamin D status and associated risk factors among adults in underserved populations.

OBJECTIVE

This study aimed to identify risk factors for vitamin D deficiency/insufficiency among Puerto Rican adults from the Boston Puerto Rican Health Study (BPRHS).

METHODS

A total of 822 adults (45-75 y, at baseline) were included in these analyses. Deficiency was defined as serum 25-hydroxyvitamin D [25(OH)D] <30 and insufficiency as 30 to <50 nmol/L. Dietary intake was assessed with a validated FFQ. Associations between risk factors, including dietary vitamin D, supplement use, ancestry, skin pigmentation, months in the past year spent in a southern climate, and serum 25(OH)D were assessed with multivariable general linear models.

RESULTS

Approximately 13% of participants were deficient in 25(OH)D and another 43% insufficient. Skin pigment was associated with 25(OH)D using 3 measures, greater African ancestry (β ± SE) (-7.74 ± 2.91, P = 0.01); interviewer assessed dark or medium, compared with white, skin tone, (-5.09 ± 2.19, P = 0.02 and -5.89 ± 1.58, P < 0.001, respectively); and melanin index of the upper inner right arm, assessed using a spectrophotometer (-2.04 ± 0.84, P = 0.02). After adjusting for ancestry, factors associated with lower serum 25(OH)D included smoking (-4.49 ± 1.58, P = 0.01); BMI (-0.21 ± 0.10, P = 0.04); and spring compared with autumn blood draw (-4.66 ± 1.68, P = 0.004). Factors associated with higher serum 25(OH)D included female sex compared with male (4.03 ± 1.58, P = 0.01); dietary vitamin D intake μg/d (0.71 ± 0.25, P < 0.004); vitamin D supplement use (4.50 ± 1.87, P = 0.02); income to poverty ratio (0.01 ± 0.01, P = 0.06), and months in a southern climate during the past year (0.96 ± 0.56, P = 0.09).

CONCLUSIONS

Vitamin D deficiency/insufficiency was prevalent in this Puerto Rican population living in the northeastern USA. Several factors were associated with this, which may assist in identifying those at risk. Interventions are needed to improve serum 25(OH)D concentration, particularly among those with limited exposure to sunlight.

COVID-19 pandemic impact on children and adolescents' mental health: Biological, environmental, and social factors

Since the Coronavirus disease 2019 (COVID-19) pandemic, caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) was announced, we had an unprecedented change in the way we organize ourselves socially and in our daily routine. Children and adolescents were also greatly impacted by the abrupt withdrawal from school, social life and outdoor activities. Some of them also experienced domestic violence growing. The stress they are subjected to directly impacts their mental health on account of increased anxiety, changes in their diets and in school dynamics, fear or even failing to scale the problem. Our aim is to bring up a discussion under different aspects and to alert public health and government agents about the need for surveillance and care of these individuals. We hope that the damage to their mental health as a result of the side effect of this pandemic can be mitigated by adequate and timely intervention.

Physical Determinants of Vitamin D Photosynthesis: A Review

Vitamin D synthesis by exposure of skin to solar ultraviolet radiation (UVR) provides the majority of this hormone that is essential for bone development and maintenance but may be important for many other health outcomes. This process, which is the only well-established benefit of solar UVR exposure, depends on many factors including genetics, age, health, and behavior. However, the most important factor is the quantity and quality of UVR reaching the skin. Vitamin D synthesis specifically requires ultraviolet B (UVB) radiation that is the minority component (<5%) of solar UVR. This waveband is also the most important for the adverse effects of solar exposure. The most obvious of which is sunburn (erythema), but UVB is also the main cause of DNA damage to the skin that is a prerequisite for most skin cancers. UVB at the Earth's surface depends on many physical and temporal factors such as latitude, altitude, season, and weather. Personal, cultural, and behavioral factors are also important. These include skin melanin, clothing, body surface area exposed, holiday habits, and sunscreen use. There is considerable disagreement in the literature about the role of some of these factors, possibly because some studies have been done by researchers with little understanding of photobiology. It can be argued that vitamin D supplementation obviates the need for solar exposure, but many studies have shown little benefit from this approach for a wide range of health outcomes. There is also increasing evidence that such exposure offers health benefits independently of vitamin D: the most important of which is blood-pressure reduction. In any case, public health advice must optimize risk versus benefit for solar exposure. It is fortunate that the individual UVB doses necessary for maintaining optimal vitamin D status are lower than those for sunburn, irrespective of skin melanin. © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research.

Skeletal Muscle and the Maintenance of Vitamin D Status

Vitamin D, unlike the micronutrients, vitamins A, E, and K, is largely obtained not from food, but by the action of solar ultraviolet (UV) light on its precursor, 7-dehydrocholesterol, in skin. With the decline in UV light intensity in winter, most skin production of vitamin D occurs in summer. Since no defined storage organ or tissue has been found for vitamin D, it has been assumed that an adequate vitamin D status in winter can only be maintained by oral supplementation. Skeletal muscle cells have now been shown to incorporate the vitamin D-binding protein (DBP) from blood into the cell cytoplasm where it binds to cytoplasmic actin. This intracellular DBP provides an array of specific binding sites for 25-hydroxyvitamin D (25(OH)D), which diffuses into the cell from the extracellular fluid. When intracellular DBP undergoes proteolytic breakdown, the bound 25(OH)D is then released and diffuses back into the blood. This uptake and release of 25(OH)D by muscle accounts for the very long half-life of this metabolite in the circulation. Since 25(OH)D concentration in the blood declines in winter, its cycling in and out of muscle cells appears to be upregulated. Parathyroid hormone is the most likely factor enhancing the repeated cycling of 25(OH)D between skeletal muscle and blood. This mechanism appears to have evolved to maintain an adequate vitamin D status in winter.