Vitamin D and PTH: data from a cross-sectional study in an equatorial population

Area of Science:

• Endocrinology
• Public Health
• Nutritional Science

Background:

• Vitamin D deficiency is a global health concern, but its prevalence in equatorial regions, particularly among diverse age groups, requires further investigation.
• Understanding vitamin D status is crucial for maintaining bone health and overall well-being.

Purpose of the Study:

• To determine the prevalence of vitamin D deficiency and insufficiency in a large, healthy equatorial population in Brazil.
• To analyze the relationship between vitamin D levels, parathyroid hormone (PTH), and demographic factors.

Main Methods:

• A cross-sectional study involving 30,224 healthy individuals from the Amazon region of Brazil.
• Serum levels of 25-hydroxy-vitamin D (25(OH)D) and intact PTH were measured using immunoassay.
• Exclusion criteria included history of diseases and abnormal levels of calcium, creatinine, glycemia, and albumin.

Main Results:

• The average 25(OH)D level was 29.1 ± 8.2 ng/mL.
• Vitamin D deficiency prevalence was 10% (Institute of Medicine criteria) and 59% (Endocrine Society criteria, defining 20-30 ng/mL as insufficiency).
• Factors like BMI, sex, living zone, and age influenced 25(OH)D levels. Elevated PTH levels were observed in subjects with vitamin D deficiency (<20 ng/mL) compared to insufficiency (20-30 ng/mL), with 26 ng/mL as a predictor for subclinical hyperparathyroidism.

Conclusions:

• The equatorial population studied exhibited a low prevalence of vitamin D hypovitaminosis, with variations across age groups.
• The Endocrine Society's criteria for vitamin D insufficiency were supported by the observed PTH data in this population.