Global prevalence and disease burden of vitamin D deficiency: a roadmap for action in low‐ and middle‐income countries

Abstract

Vitamin D is an essential nutrient for bone health and may influence the risks of respiratory illness, adverse pregnancy outcomes, and chronic diseases of adulthood. Because many countries have a relatively low supply of foods rich in vitamin D and inadequate exposure to natural ultraviolet B (UVB) radiation from sunlight, an important proportion of the global population is at risk of vitamin D deficiency. There is general agreement that the minimum serum/plasma 25-hydroxyvitamin D concentration (25(OH)D) that protects against vitamin D deficiency-related bone disease is approximately 30 nmol/L; therefore, this threshold is suitable to define vitamin D deficiency in population surveys. However, efforts to assess the vitamin D status of populations in low- and middle-income countries have been hampered by limited availability of population-representative 25(OH)D data, particularly among population subgroups most vulnerable to the skeletal and potential extraskeletal consequences of low vitamin D status, namely exclusively breastfed infants, children, adolescents, pregnant and lactating women, and the elderly. In the absence of 25(OH)D data, identification of communities that would benefit from public health interventions to improve vitamin D status may require proxy indicators of the population risk of vitamin D deficiency, such as the prevalence of rickets or metrics of usual UVB exposure. If a high prevalence of vitamin D deficiency is identified (>20% prevalence of 25(OH)D < 30 nmol/L) or the risk for vitamin D deficiency is determined to be high based on proxy indicators (e.g., prevalence of rickets >1%), food fortification and/or targeted vitamin D supplementation policies can be implemented to reduce the burden of vitamin D deficiency-related conditions in vulnerable populations.

Genotype-independent association between vitamin D deficiency and polycystic ovarian syndrome in Lahore, Pakistan

“…Exploratory analyses investigating 25(OH)D cut-offs of 15 ng/ml (aOR 3.41, 95% CI 1.77 to 6.57), 20 ng/ml (aOR 1.79, 95% CI 0.96 to 3.37), or analyzing 25(OH)D as a continuous variable (aOR 0.98, 95% CI 0.96 to 1.01) showed consistent inverse associations between 25(OH)D level and PCOS risk. Our findings with regard to other factors associated with PCOS, such as higher BMI, reduced physical exercise, higher fasting glucose levels and positive family history are also in keeping with the literature [22][23][24][25] .…”

“…The high prevalence of vitamin D deficiency seen among participants in the current study is in keeping with our previous study in Lahore showing a high prevalence of vitamin D deficiency among women of reproductive age 20 . These and other studies reporting high rates of vitamin D deficiency in other groups 21 , highlight that vitamin D deficiency is a major public health problem in Pakistan 22 . The adjusted odds ratio for the association between vitamin D deficiency at the pre-specified 25(OH)D cut-off of 10 ng/ml was higher than has been reported elsewhere; this primarily reflects the very low prevalence of 25(OH)D values <10 ng/ml among controls in the current study.…”

Total, Bioavailable, and Free Vitamin D Levels and Their Prognostic Value in Pulmonary Arterial Hypertension

“…There is no consensus on the threshold levels for 25(OH)vitD deficiency, its assessment, and its treatment, and clinical practice is inconsistent. However, even using conservative thresholds in population surveys, an important proportion of the global population shows vitD deficiency due to insufficient solar light exposure and/or reduced dietary intake [7].…”

A Potential Linking between Vitamin D and Adipose Metabolic Disorders

“…e mechanism of vitamin D action is through its active form, 1α, 25-dihydroxyvitamin D 3 [1α, 25(OH) 2 D 3 ], which regulates the transcription of target genes and thus plays an important role in calcium homeostasis and metabolism [5][6][7]. Vitamin D deficiency or insufficiency is still a common issue in developing countries [8,9]. Among 734 adolescents ranging from 12 to 18 years, 87.6% of participants had vitamin D deficiency [10].…”