Association of Vitamin D Levels in Coal Miners: A Case-Control Study

Strategies for preventing bone loss in populations with insufficient calcium and vitamin D intake

Calcium and vitamin D are essential nutrients for maintaining skeletal health, yet deficiencies in these nutrients are particularly widespread in regions such as Asia and Africa. Inadequate intake of these nutrients in these areas has been associated with diminished bone integrity and a rising incidence of osteoporosis. This review examines the underlying mechanisms of bone loss driven by calcium and vitamin D deficiencies, emphasizing their crucial roles in bone metabolism. It also presents strategies to improve nutrient intake, such as fortification of staple foods and supplementation, along with lifestyle modifications including increased physical activity, sun exposure, and dietary education, to prevent bone loss effectively. Special consideration is given to vulnerable populations, including older adults, individuals with limited sun exposure, and those with dietary restrictions, who are at higher risk of deficiency. The review further evaluates public health strategies, including government-initiated fortification and educational programs, as essential measures for tackling widespread nutrient deficiencies. Lastly, it explores future avenues for addressing calcium and vitamin D deficiencies, including the potential role of digital health tools, personalized nutrition, and innovative public health policies to alleviate the global burden of bone-related diseases.

Survival patterns of neonates born to adolescent mothers and the effect of pregnancy intentions and marital status on newborn survival in Kenya, Uganda, and Tanzania, 2014-2016

Background

Adolescent pregnancy and associated neonatal mortality are major global health challenges. In low-income settings where 90% of the 21 million global adolescent pregnancies occur, half are unintended and a fifth experience unsafe abortion. In Kenya, Uganda, and Tanzania, the survival patterns of neonates born to adolescents are unclear.

Objectives

To assess survival patterns among neonates born to adolescents and the effect of pregnancy intentions and marital status on survival in Kenya, Uganda, and Tanzania.

Methods

Cross-sectional data from demographic and health surveys in Kenya, Uganda, and Tanzania 2014–2016 were used. Kaplan-Meier estimates investigated patterns of neonatal survival among adolescent mothers, aged 15–19 years, compared to mothers aged 20–29 years. Cox proportional hazards regression determined the hazard ratios (HR) for the predictors of neonatal survival.

Results

About 50% of adolescent pregnancies were unintended and neonatal death rate was twice as high than older mothers (26.6 versus 12.0 deaths/1000 live births). The median survival time was two days for adolescent-born babies and four days among older mothers. The hazard of death for all adolescent-born neonates was about twofold that of 20–29 years-old-mothers, HR 1.80 (95% CI 1.22–2.63). Among married adolescents with unintended newborn pregnancies, the HR was 4-folds higher than corresponding older mothers, HR 4.08 (95% CI 1.62–10.31). Among married, primiparous adolescents with unintended pregnancies, the HR was six times higher than corresponding older mothers.

Conclusion

Our findings reveal how unintended pregnancies and deaths of neonates born to adolescents contribute substantially to preventable neonatal deaths in East Africa. Full implementation of existing adolescent health policies and utilization of contraceptives should be ensured. Partnership with youths and novel efforts that address sociocultural norms to reduce adolescent pregnancies or marriage should be supported. Regulations requiring adolescents’ obstetric care conducted by only skilled personnel should be introduced and implemented.

Vitamin D Status and Its Correlation With Anthropometric and Biochemical Indicators of Cardiometabolic Risk in Serbian Underground Coal Miners in 2016

The status of vitamin D in underground working coal miners and its association with their cardiometabolic health is rarely studied. This study aimed to examine vitamin D (VitD) status in Serbian underground coal miners and to correlate it with anthropometric and laboratory indicators of cardiometabolic risk. Nutritional data (food frequency questionnaire, FFQ, and two times repeated 24 h recall), anthropometric data (including segmental analysis by bio-impedance analyzer TANITA BC-545N), arterial tension, and biochemical and hematological data of 103 coal miners (aged 22-63 years) were correlated with their late summer (early September) serum 25 (OH)D levels (measured by HPLC). 68.9% of the studied coal miners were overweight/obese, and 48.5% had metabolic syndrome. Their mean VitD nutritional intakes were low: 5.3 ± 3.8 μg/day (FFQ) and 4.9 ± 8 μg/day (24 h recalls), but their mean serum 25 (OH)D levels were surprisingly high (143.7 ± 41.4 nmol/L). Only 2.9% of the coal miners had 25(OH)D levels lower than 75 nmol/L (indicating an insufficient/deficient status), while 63.2% had values above 125 nmol/L (upper optimal limit), and even 10.7% had values above 200 nmol/L. There were no statistical differences in 25 (OH)D levels in the coal miners with or without metabolic syndrome (or overweight/obesity). Interestingly, 25(OH)D levels had significant positive correlations with body mass index (BMI), fat mass (FM), fat mass percentage (FM%), limbs FM%, serum triglycerides, GGT, AST, ALT, and ALT/AST ratio, and had significant negative correlations with serum HDL-cholesterol and age. All these correlations were lost after corrections for age, FM, FM%, and legs FM%. In Serbian coal miners, high levels of early September VitD levels were observed, indicating sufficient non-working-hour sun exposure during the summer period. Furthermore, the unexpected positive correlations of VitD levels with anthropometric and biochemical parameters indicative of obesity, metabolic syndrome, and fatty liver disease were found. More research is needed on the VitD status of coal miners (particularly in the winter period) and its relationship with their cardiometabolic status.