Metabolically Obese Individuals of Normal Weight Have a High Risk of 25-Hydroxyvitamin D Deficiency

Abstract

Background: Vitamin D status is related to obesity-related metabolic disorders. We investigated the risk of 25-hydroxyvitamin D [25(OH)D] deficiency among different metabolic phenotypes.

Methods: This prospective cross-sectional study evaluated 1,292 individuals who were ≥40 years old. Participants were classified as metabolically healthy and normal weight (MHNW), metabolically obese but normal weight (MONW), metabolically healthy but obese (MHO) or metabolically unhealthy and obese (MUO). The demographic and clinical characteristics, as well as plasma 25(OH)D levels, were compared between the 4 groups.

Results: The prevalences of MHNW, MONW, MHO and MUO were 32.1%, 19.3%, 17.9% and 30.7%, respectively. Approximately 58.5% participants had vitamin D deficiency, and vitamin D deficiency was more common in the MONW (68.7%) and MUO (73.6%) groups (MHNW, 42.7 and MHO, 50.2%). The MONW and MUO groups had lower 25(OH)D levels (versus the MHNW and the MHO groups). Among vitamin D-deficient participants, the MONW group exhibited increased risks of abdominal obesity (odds ratio [OR]: 3.28, P = 0.005), hypertension (OR: 3.08, P = 0.003) and elevated C-reactive protein (OR: 1.97, P = 0.03). In addition, the MUO group exhibited increased risks of hypertriglyceridemia (OR: 2.57, P = 0.001), insulin resistance (OR: 2.37, P = 0.001) and elevated C-reactive protein level (OR: 2.09, P = 0.003).

Conclusions: Individuals who were MONW and MUO had increased risks of vitamin D deficiency (versus MHNW and MHO), and individuals with vitamin D deficiency had worse metabolic status. Vitamin D supplementation may improve the metabolic status of individuals who are MONW or MUO.

Keywords: Metabolically healthy but obese; Metabolically obese but normal weight; Metabolically unhealthy and obese; Obesity; Vitamin D deficiency.