The relationship between vitamin D deficiency, body composition, and physical/cognitive functions

Area of Science:

• Endocrinology and Metabolism
• Nutritional Science
• Body Composition Analysis

Background:

• Vitamin D deficiency is a global health concern with widespread effects on tissues and functions.
• Previous studies explored vitamin D's relation to body composition and physical/cognitive functions separately.
• A comprehensive evaluation of these interconnected parameters was lacking.

Purpose of the Study:

• To investigate the relationship between vitamin D deficiency and body composition, including skin, subcutaneous fat, and muscle thicknesses.
• To assess the association of vitamin D levels with physical functions (strength, speed, balance) and cognitive status.
• To provide a holistic view of vitamin D's impact on overall health metrics.

Main Methods:

• 203 adults (78 males, 125 females, aged 19-91) with recent 25-OH-vitamin D measurements were included.
• Ultrasonography assessed skin, subcutaneous fat, and muscle thicknesses on the hand, forearm, arm, and thigh.
• Physical function tests (handgrip strength, gait speed, TUG, CST) and cognitive assessment (MMSE) were performed.

Main Results:

• Vitamin D deficient individuals ( < 20 ng/ml) exhibited significantly thicker subcutaneous fat tissues compared to controls (≥ 20 ng/ml).
• No significant differences were found in skin/muscle thickness, physical function, or cognitive scores between groups.
• Linear regression revealed Body Mass Index (BMI) independently associated with subcutaneous fat, and vitamin D deficiency linked to increased fat in females and forearm fat in males.

Conclusions:

• Vitamin D deficiency, alongside BMI, is independently associated with increased regional subcutaneous fat.
• Ultrasonography proves valuable for assessing body composition in clinical contexts related to vitamin D status.
• These findings emphasize the role of vitamin D in fat distribution and the importance of supplementation and balanced diets.