Seasonal variation of 25-Hydroxyvitamin D and indices of carbohydrate and lipid metabolism in postmenopausal women

Abstract

Background Some studies indicate vitamin D’s significant contribution to metabolic processess. Therefore, the purpose of this study was to evaluate the level of carbohydrate and lipid metabolism indices in relation to seasonal changes in 25-hydroxyvitamin D (25(OH)D) concentration in postmenopausal women. Methods Sixteen postmenopausal women meeting health criteria and not using vitamin D supplementation were included in the study. Seasonal variation of somatic features and the serum concentration of 25(OH)D, glucose, insulin, parathormon, sclerostin and lipid profile were determined on two terms (autumn-winter). Results Comparative analysis of the variables between the study terms revealed a marked decrease in the concentration of 25(OH)D (p ≤ 0.0001), insulin (p < 0.05), insulin resistance index (HOMA-IR), (p < 0.05). The significant positive correlations of changes (Δ) between autumn and winter in 25(OH)D with body mass (p < 0.05), and fat mass (p ≤ 0.01), measured in the first study term, in the group of women with normal body mass index (BMI), and negative correlation with fat mass (p < 0.05) in women with a BMI value above the reference values, were found. The relationship analysis showed that in women with normal BMI, the decrease in 25(OH)D concentrations was greater when the body fat percentage was higher, whereas in women with a BMI value above the reference values, the higher the fat percentage, the smaller was the decrease in 25(OH)D concentration. Conclusions Seasonal changes in 25(OH)D concentration did not significantly affect the concentration of carbohydrate and lipid metabolism indices. The magnitude of decline in 25(OH)D levels depends on the fat mass. We suppose that environmental or lifestyle-related factors, e.g., nutritional behaviours, may have had more influence on metabolic indices than changes in 25(OH)D.

Sex and Age Differences Modulate Association of Vitamin D with Serum Triglyceride Levels

“…Moreover, young urban people must often spend considerable amounts of time indoors for work and may engage in few outdoor activities, leading to low sun exposure and a consequently higher risk of vitamin D deficiency. Our study showed that participants had higher serum 25(OH)D levels during extended summer than those during extended winter, which was similar to previous findings reporting the seasonal variations in serum 25(OH)D concentrations [19,21,22]. In the present study, we also observed that women are more prone to vitamin D deficiency than men; this result is consistent with several other studies [25][26][27].…”

“…The serum 25(OH)D levels are highest during late summer and lowest during late winter in northern countries [ 18 , 19 , 20 ]. Previous investigations have shown that the serum 25(OH)D levels in winter may be decreased by approximately 25–50% on average as compared to those in summer [ 21 , 22 ]. Accordingly, seasonal variations should be taken into consideration when measuring serum 25(OH)D levels and treating vitamin D deficiency.…”

Influence of Nordic walking with poles with an integrated resistance shock absorber on carbohydrate and lipid metabolic indices and white blood cell subpopulations in postmenopausal women

“…Receptors for vitamin D have been identified in pancreatic cells ( Christakos et al, 2016 ), adipose tissue, and the liver ( Cimini et al, 2019 ), indicating that this vitamin is involved in energy metabolism. However, in our previous study, we did not find significant relationships between seasonal changes in 25(OH)D concentration and levels of carbohydrate and lipid metabolic indices in women who did not engage in physical activity during the study period ( Huta-Osiecka et al, 2021 ). In the present study, we also found no association between 25(OH)D concentrations and metabolic indices, as well as no correlation between the changes in metabolic indices (comparing levels before and after training) and 25(OH)D levels either for the whole group or for RSA and NW groups.…”

“…Therefore, we can conclude that the magnitude of changes in these indices was not determined by fat mass content. However, recent studies have revealed a significant relationship between seasonal changes in 25(OH)D concentration and body fat percentage measured at the beginning of the study (autumn period) in postmenopausal women ( Huta-Osiecka et al, 2021 ).…”

“…Blood serum was stored at −70 °C until biochemical analyses were performed. Biochemical analysis were performed as previously described in Huta-Osiecka et al (2021) . Serum 25(OH)D concentration was determined by chemiluminescent immunoassay (CLIA), using the LIAISON® 25 OH Vitamin D TOTAL Assay (DiaSorin Inc, Saluggia, Italy), with sensitivity 4 ng/ml.…”