Air Pollution's Impact On Vitamin D Synthesis

Vitamin D is a critical nutrient for preventing several chronic diseases, and its deficiency can cause many illnesses. Air pollution has been reported as a significant factor in vitamin D deficiency. Vitamin D is either produced in the skin by the non-enzymatic conversion of provitamin D or delivered from food sources. The former process, which occurs under the influence of the sun's ultraviolet B (UVB) radiation, covers as much as 90% of total body needs. Therefore, inadequate radiation or insufficient cutaneous absorption of UVB are regarded as major causes of vitamin D deficiency.

Air pollution affects vitamin D levels by reducing sun exposure, especially UVB radiation. Tropospheric ozone and particulate matter are two important air pollutants associated with vitamin D deficiency. They primarily affect vitamin D levels by limiting sun exposure.

Recent studies have demonstrated that tropospheric ozone and particulate matter are independent risks to vitamin D levels and cause deficiency. However, obtaining comprehensive conclusions on the impact of air pollution on vitamin D deficiency is necessary.

Air pollution reduces sun exposure, especially UVB radiation, which is necessary for vitamin D synthesis

Air pollution is a major factor in determining the amount of solar UVB radiation that reaches the Earth's surface. It has been proven by both observational and prospective studies that air pollution, especially high tropospheric ozone content, may play a significant role in the development of vitamin D deficiency. Tropospheric ozone can efficiently absorb UVB radiation and decrease the amount of photons reaching the ground level. The level of air pollution is inversely related to the extent of solar UVB that reaches the Earth's surface. Therefore, people in areas with high levels of air pollution generally spend less time outdoors.

The skin synthesis of vitamin D occurs through the action of sunlight. Sun exposure accounts for more than 90% of vitamin D production in humans. However, air pollution can reduce the effectiveness of sun exposure in producing vitamin D in the skin by absorbing and scattering solar UVB radiation.

Several studies have shown that vitamin D deficiency is associated with air pollution. A cross-sectional study conducted in Belgium on postmenopausal women engaged in outdoor activities showed that the tropospheric ozone increased the prevalence of a low vitamin D status. In this study, the serum levels of vitamin D and parathormone (PTH) of 47 women living in rural areas were compared with those of 38 women living in Brussels. As expected, in urban residents, the prevalence of vitamin D insufficiency was significantly higher than in rural residents (38% vs 18%), while the concentration of ground-level ozone was three times higher in urban areas than in rural areas.

In a cross-sectional study conducted in urban and rural areas of Iran, 200 healthy women living in two separate zones of approximately similar latitude, but with different levels of air pollution, were included. The authors found that the prevalence of hypovitaminosis D was higher in women living in the more polluted area compared to those living in the less polluted area, confirming that air pollution plays a significant independent role in vitamin D deficiency.

In addition, a study investigated the association between gestational exposure to ambient urban air pollution and vitamin D levels in the cord blood in French mother-child pairs. The results showed that pollutant exposure, especially during late pregnancy, contributed to lower vitamin D levels in offspring, thus affecting the child's risk of developing diseases later in life.

The association between air pollution and low vitamin D status was also investigated among children. Children living in a highly polluted area had average serum concentrations of 25(OH)D significantly lower by 54% compared to those living in a less polluted area of the city.

In summary, air pollution affects vitamin D levels by reducing sun exposure, especially UVB radiation.

Air pollution is an independent risk factor for vitamin D deficiency

Air pollution is a chief factor determining the extent of solar UVB that reaches the Earth's surface. Several epidemiological studies, representing different populations living in different geographic latitudes, indicate that atmospheric pollution (especially high tropospheric ozone content) may play a significant independent role in the development of vitamin D deficiency. As a result, the prevalence of vitamin D hypovitaminosis among urban residents can be more than twice as high as that of rural inhabitants.

The level of air pollution is inversely related to the extent of solar UVB that reaches the Earth's surface. Consequently, more polluted areas have less UVB passage, resulting in lower vitamin D cutaneous synthesis.

Recent studies have demonstrated that tropospheric ozone and particulate matter are independent risks to vitamin D levels and cause deficiency.

In a cross-sectional study conducted in Belgium on postmenopausal women engaged in outdoor activities, it was shown that tropospheric ozone increased the prevalence of a low vitamin D status. In this study, the serum levels of vitamin D and parathormone (PTH) of 47 women living in rural areas were compared with those of 38 women living in Brussels. As expected, in urban residents, the prevalence of vitamin D insufficiency was significantly higher than in rural residents (38% vs 18%), while the concentration of ground-level ozone was three times higher in urban areas than in rural areas.

In a cross-sectional study conducted in urban and rural areas of Iran, it was found that the prevalence of hypovitaminosis D was higher in women living in the more polluted area compared to those living in the less polluted area, confirming that air pollution plays a significant independent role in vitamin D deficiency.

In another study, it was investigated whether gestational exposure to ambient urban air pollution was associated with levels of vitamin D in the cord blood in French mother-child pairs. It was found that pollutant exposure, especially during late pregnancy, contributed to lower vitamin D levels in offspring, thus affecting the child's risk of developing diseases later in life.

In summary, air pollution is an independent risk factor for vitamin D deficiency.

The prevalence of vitamin D deficiency is higher in urban residents compared to rural residents

Vitamin D is a fat-soluble hormone that plays a critical role in maintaining phosphorus and calcium homeostasis in the human body. It is also involved in regulating cell growth and immunity. The body synthesises vitamin D3 from 7-dehydrocholesterol in the skin under the influence of UVB radiation from the sun. However, urban residents tend to have a higher prevalence of vitamin D deficiency compared to their rural counterparts. This disparity can be attributed to various factors, including air pollution, lifestyle choices, and dietary habits.

Air pollution is one of the primary factors contributing to the higher prevalence of vitamin D deficiency in urban areas. Particulate matter, nitrogen dioxide, and nitrogen oxides are among the main components of air pollution that absorb and scatter solar UVB radiation, reducing its availability for vitamin D synthesis in the skin. A study by Chenlu Yang and colleagues found a negative association between air pollution and serum vitamin D levels. They observed that long-term exposure to ambient air pollutants led to a decrease in serum vitamin D concentrations. This effect was more pronounced in females.

Lifestyle choices and dietary habits also play a role in the higher prevalence of vitamin D deficiency among urban residents. Urban dwellers often lead more sedentary lifestyles, spending less time outdoors and engaging in physical activities. This reduced sun exposure can contribute to lower vitamin D synthesis in the skin. Additionally, urban diets may be inadequate in providing sufficient vitamin D, as natural dietary sources of vitamin D are limited.

Furthermore, urban areas tend to have a higher proportion of individuals with certain demographic characteristics, such as older adults and individuals with darker skin pigmentation. These factors can also influence vitamin D synthesis and absorption. Older adults have a decreased capacity for vitamin D synthesis in the skin due to ageing, while darker skin pigmentation reduces the skin's ability to absorb UVB radiation.

It is worth noting that some studies have reported conflicting results, with vitamin D deficiency being more prevalent in rural areas. These discrepancies may be attributed to local microclimates, genetic factors, and other variables that require further investigation.

Overall, the higher prevalence of vitamin D deficiency in urban residents compared to rural residents is a complex issue influenced by a combination of factors, including air pollution, lifestyle choices, dietary habits, and demographic characteristics. Addressing these factors through public health interventions and individual lifestyle modifications can help mitigate the risk of vitamin D deficiency in urban populations.

Air pollution may cause vitamin D deficiency by reducing outdoor activity

Air pollution is a major global public health issue, affecting the daily lives of people and predisposing them to a number of health issues. It is known that exposure to air pollution affects multiple organ systems and functions, including the cardiovascular, respiratory, and sleeping patterns.

Vitamin D is a critical component in maintaining phosphorus and calcium homeostasis and regulating cell growth and immunity. Vitamin D deficiency has been linked to various health issues, including fractures, osteoporosis, autoimmune diseases, cancers, microbial infections, diabetes, and cardiovascular disease.

Air pollution is a main determinant of the ground level of UVB, which is essential for the skin synthesis of vitamin D. Studies have reported that ambient air pollutants can absorb and diffuse solar irradiation, thus decreasing ground levels of UVB necessary for vitamin D synthesis.

In addition, people in areas with high air pollution levels generally spend less time outdoors, further reducing the availability of vitamin D. This suggests that air pollution may cause vitamin D deficiency by reducing outdoor activity.

Air Pollution and Outdoor Activity

Air pollution is a complex mixture of man-made pollutants and natural sources. It can be caused by natural factors, such as volcanic eruptions, wildfires, wind currents, and trees, as well as human activities, such as emissions from factories, power plants, and vehicles.

Air pollution can have a significant impact on human health, including triggering symptoms of asthma, causing breathing problems, and increasing the risk of heart disease and cancer.

Impact on Vitamin D Synthesis

Vitamin D is primarily synthesized in the skin upon exposure to sunlight. However, air pollution can absorb and diffuse solar irradiation, reducing the ground levels of UVB necessary for vitamin D synthesis.

Studies have found a negative association between air pollution and vitamin D levels. Higher levels of air pollution are linked to lower vitamin D levels or an increased risk of vitamin D deficiency.

Reducing Outdoor Activity

Air pollution can also reduce outdoor activity, further contributing to vitamin D deficiency. People in areas with high air pollution levels may spend less time outdoors, reducing their exposure to sunlight and, consequently, their vitamin D synthesis.

Gender Differences

It is worth noting that the effects of air pollution on vitamin D levels may be more pronounced in females. One study found that females exposed to higher levels of air pollution had significantly lower vitamin D levels compared to males.

In conclusion, air pollution may cause vitamin D deficiency by reducing outdoor activity and decreasing the availability of UVB necessary for vitamin D synthesis. Additionally, people in highly polluted areas may be less inclined to engage in outdoor activities, further contributing to vitamin D deficiency.

Air pollution can increase the risk of developing diseases associated with vitamin D deficiency

Air pollution is a dominant factor influencing the extent of solar UVB that reaches the Earth's surface. It was proven by observational and prospective studies, performed on different populations living in different geographic latitudes, that atmospheric pollution (especially high tropospheric ozone content) may play a significant independent role in the development of vitamin D deficiency. Tropospheric ozone can efficiently absorb UVB radiation and decrease the amount of photons reaching ground level. It was proved that the level of air pollution is inversely related to the extent of solar UVB that reaches the Earth's surface. Since industrial areas are those with the highest intensity of air pollution, the prevalence of vitamin D hypovitaminosis among urban residents can be more than twice as high compared to rural inhabitants.

Vitamin D is an essential nutrient for preventing several chronic diseases, and vitamin D deficiency causes many diseases. Vitamin D skin synthesis, which takes place under the influence of the sun's ultraviolet B (UVB) radiation, covers as much as 90% of total body needs. Therefore, inadequate radiation or insufficient cutaneous absorption of UVB are regarded as major causes of vitamin D deficiency.

Several diseases are recognized as the results of air pollution. From reviewing the literature, we aimed to determine whether air pollution causes or accelerates the progression of vitamin D deficiency. Considerable efforts have gone into elucidating the relationship between disease and air pollutant exposure. However, the studies and published data presented here confirm positive relationships between vitamin D deficiency and air pollutants.

To determine vitamin D deficiency prevalence among the global population, relevant papers have been presented. Furthermore, we present some studies that discuss the relationship between air pollution and vitamin D levels.

Recent studies have demonstrated that tropospheric ozone and particulate matter are independent risks to vitamin D levels and cause deficiency. Relation of vitamin D deficiency prevalence and air pollution was observed regardless of age and gender.

Air pollution affects vitamin D levels by reducing sun exposure, especially UVB radiation.

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