Vitamin D deficiency associations with metabolic, bone turnover and adverse general health markers in community free living adults

Association of vitamin D levels with anthropometric and adiposity indicators across all age groups: a systematic review of epidemiologic studies

Objectives

It has not been established whether vitamin D deficiency is associated with anthropometric state; therefore, this systematic review examined the relationship between serum vitamin D levels with anthropometrics and adiposity across different ages.

Methods

Studies that examined vitamin D deficiency with adiposity measures in different age groups were searched in the PubMed, Scopus, Embase, and Google Scholar databases until November 2023. Two investigators independently reviewed titles and abstracts, examined full-text articles, extracted data, and rated the quality in accordance with the Newcastle-Ottawa criteria.

Results

Seventy-two studies, with a total of 59,430 subjects, were included. Of these studies, 27 cross-sectional studies and one longitudinal study (with 25,615 participants) evaluated the possible link between 25(OH)D serum concentrations and anthropometric/adiposity indices in the pediatric population. Forty-two cross-sectional studies and two cohort investigations (with 33,815 participants) investigated the relationship between serum 25(OH)D levels and adiposity measures in adults and/or the elderly population. There is evidence supporting links between vitamin D deficiency and obesity, and revealed an inverse association between vitamin D and adiposity indicators, specifically in female subjects. However, the effects of several confounding factors should also be considered.

Conclusion

Most published studies, most of which were cross-sectional, reported a negative association between vitamin D and female adiposity indicators. Therefore, serum vitamin D levels should be monitored in overweight/obese individuals.

Changes in bone turnover markers in adolescents with gastroesophageal reflux disease treated with lansoprazole

Background

Proton pump inhibitors (PPIs) have been suggested to lead to bone resorption, while the effects of PPIs on the bone mineral metabolism in children has received only limited attention in literature to date. The present study investigates whether lansoprazole alters bone turnover markers in adolescents with gastroesophageal reflux disease (GERD).

Patients and methods

Included in the study were adolescents aged 16-18 with GERD and a healthy volunteers group. The GERD patient group was treated with lansoprazole 30 mg once daily for eight weeks. The serum calcium, phosphorus, magnesium, alkaline phosphatase (ALP), parathormone (PTH), 25 (OH) vitamin D, osteocalcin and urinary calcium, creatinine, deoxypyridinoline (DPD), collagen type-1 crosslinked C-telopeptide (CTX) and collagen type-1 crosslinked N-telopeptide (NTX) of both groups were studied before and after the end of the treatment.

Results

A comparison of the 30 patients with GERD and the 30 volunteers revealed no significant difference in the serum calcium, phosphorus, magnesium, ALP, urinary calcium/creatinine ratio, 25 (OH) vitamin D and PTH levels measured before and after the lansoprazole treatment, while the osteocalcin, DPD, CTX and NTX values were found to be higher after treatment when compared to those at pre- treatment.

Conclusions

The results of this study reveal that eight weeks of treatment with 30 mg lansoprazole daily increased the bone turnover markers of CTX, NTX, DPD and osteocalcin in adolescents aged 16-18.

Vitamin D, exercise, and immune health in athletes: A narrative review

Vitamin D exerts important extra-skeletal effects, exhibiting an exquisite immune regulatory ability, affecting both innate and adaptive immune responses through the modulation of immunocyte function and signaling. Remarkably, the immune function of working skeletal muscle, which is fully recognized to behave as a secretory organ with immune capacity, is under the tight control of vitamin D as well. Vitamin D status, meaning hormone sufficiency or insufficiency, can push toward strengthening/stabilization or decline of immune surveillance, with important consequences for health. This aspect is particularly relevant when considering the athletic population: while exercising is, nowadays, the recommended approach to maintain health and counteract inflammatory processes, “too much” exercise, often experienced by athletes, can increase inflammation, decrease immune surveillance, and expose them to a higher risk of diseases. When overexercise intersects with hypovitaminosis D, the overall effects on the immune system might converge into immune depression and higher vulnerability to diseases. This paper aims to provide an overview of how vitamin D shapes human immune responses, acting on the immune system and skeletal muscle cells; some aspects of exercise-related immune modifications are addressed, focusing on athletes. The crossroad where vitamin D and exercise meet can profile whole-body immune response and health.