Abdominal fat and muscle weakness in women are linked to vitamin D deficiency

In a recent study published in the journal nutrientsResearchers investigated the association between vitamin D levels and body composition in women between the ages of 20 and 49.

Their findings show that women with insufficient vitamin D levels have higher body mass index and waist-to-height ratio, as well as lower muscle mass index after adjusting for body mass index (BMI).

This suggests a potential impact of vitamin D deficiency on body fat and muscle tissue, and these findings, particularly waist-to-height ratio and muscle mass index, should be addressed to address the metabolic effects of vitamin D deficiency. It emphasizes the importance of incorporating this into medical practice.

Study: Relationship between vitamin D deficiency and body fat and muscle mass in adult women of childbearing age. Image credit: Dzmitry Sarmont / Shutterstock

background

The prevalence of vitamin D deficiency (VDD) is high among women of childbearing age, especially those who exhibit obesity.

Understanding the effects of vitamin D on different tissues, such as skeletal muscle and adipose tissue, is critical for bone, reproductive, immune, and mental health.

Although studies have focused on the relationship between obesity and VDD using BMI and waist circumference measurements, other important factors that can influence body fat distribution are often overlooked.

Furthermore, although the association between VDD and skeletal muscle mass is significant and influences muscle strength and function, studies in premenopausal women are lacking.

About research

This study aimed to investigate the association between body composition and vitamin D status in adult women of childbearing age, providing valuable insight into women’s overall health and well-being.

A cross-sectional design was conducted between August 2018 and August 2019 among adult Brazilian women aged 20 to 49 years. This included clinical nutritional history, anthropometric measurements, and biochemical evaluation.

The required sample size was determined based on the prevalence of VDD in Brazil. Researchers used high-performance liquid chromatography to measure circulating concentrations of 25-hydroxyvitamin D (25(OH)D), with 30 ng/mL or more sufficient and 20 ng/mL or more but less than 30 ng/mL. was classified as insufficient and less than 20 ng/mL as inadequate. It is insufficient.

Anthropometric evaluation included measurements of weight, height, waist circumference, hip circumference, triceps subcutaneous fat, and arm circumference. Indicators such as muscle mass index, BMI, and waist-hip ratio (WHR) were calculated using established formulas.

Statistical analyzes were performed using SPSS, including tests of normality, central tendency, variance, Mann-Whitney coefficient, Kruskal-Wallis coefficient, and Spearman coefficient to measure correlation.

Investigation result

The study sample consisted of 124 women with a mean age of 34.1 years and a mean BMI of 24.2 kg/m². Of these, 66.9% showed a normal BMI, 9.7% were classified as obese, and the remaining 23.4% were classified as overweight.

The mean circulating 25(OH)D concentration was 28.8 ng/mL, with 36.3% of participants classified as vitamin D sufficient, 63.7% inadequate, 19.4% deficient, and 44.4% vitamin D deficient. it was done.

Body composition analysis of participants revealed that women with sufficient vitamin D levels had significantly lower body mass index (BAI), while women with insufficient vitamin D had higher BAI and waist-to-height ratio (WHtR) Became.

Additionally, women with adequate vitamin D levels had higher BMI-adjusted muscle mass index (SMI BMI) than women with inadequate vitamin D levels.

When participants were separated by both vitamin D status and BMI, the researchers observed significant differences in various measures of body composition.

For example, normal weight women with insufficient vitamin D levels had higher WHtR than women with adequate vitamin D levels, but overweight women with insufficient vitamin D had higher WHtR than women with adequate vitamin D levels. They also had higher body weight, hip circumference, and Bellarmino-Weitzberg index (BeW).

Correlation analysis revealed a negative correlation between circulating 25(OH)D concentrations and waist circumference (WC), WHtR, fat mass index (FMI), body fat percentage (% BF), and fat-to-muscle ratio (FMR). One thing has become clear. SMI positive correlation with BMI.

Researchers found that in women with insufficient vitamin D levels, there was a negative association between 25(OH)D and visceral adiposity index (VAI), which was greater in women exhibiting VDD. It was remarkable.

Women with insufficient vitamin levels showed a negative correlation between % BF and 25(OH)D, whereas women with VDD showed a negative correlation with VAI and triceps subcutaneous fat (TSF). showed the relationship.

conclusion

Researchers observed a negative association between vitamin D status and body fat, especially abdominal fat, and a positive association with muscle mass. In particular, indicators such as SMI, BMI, and WHtR have emerged as valuable clinical indicators.

The prevalence of VDD in premenopausal adult women is consistent with existing literature and indicates that the problem is widespread. Additionally, a positive association was found between adequate amounts of vitamin D and increased muscle mass, highlighting the importance of maintaining adequate vitamin D levels for optimal muscle function.

Conversely, vitamin D insufficiency was associated with increased body fat percentage and central obesity. These findings highlight the importance of assessing body composition beyond traditional measures such as BMI.

Additionally, vitamin D deficiency was strongly correlated with visceral fat accumulation, highlighting potential cardiometabolic risks. This study suggests incorporating body composition variables such as WHtR and SMI BMI into clinical practice to reduce the metabolic effects of vitamin D deficiency.

However, the cross-sectional design and lack of sun exposure assessment limit the study’s ability to establish causal relationships or generalize results beyond specific demographic groups.