Confusions in Vitamin D Estimation and Interpretation

Abstract

Role of vitamin D in calcium and phosphorous regulation and in bone metabolism is a well known fact and so, was the need for diagnosing vitamin D deficiency in osteoporosis, osteomalacia and fractures. Discovery of the presence of vitamin D receptor in several tissues has lead to several research works to know the effect of vitamin D on these tissues. This has thrown light on previously blind areas. Vitamin D deficiency is known to be present in cancers, infectious diseases, autoimmune disorders,cardiovascular disease type 2 diabetes mellitus. These findings have resulted in increased laboratory requests for vitamin D estimation. This article aims at providing insight 1. into vitamin D and its metabolic effects , 2.different forms of vitamin D 3.existing methods to estimate vitamin D 4. Selection of the method for estimation, and reference methods for vitamin D estimation, 5. Factors causing variations in vitamin D results, 6. internal and external quality control issues,7.Interpretation of results.

Epidemic of Vitamin D Deficiency Among Tea Plantation Women of Assam, India

“…The US Endocrine society (2011) categorizes a serum vitamin D value of 20 ng/ml to be expected. This value is accepted in most laboratories in India as the range given by them corresponds to most India populations and is considered an appropriate classification to determine vitamin D deficiency in the Indian population (Rani, 2014).…”

“…In 2014, Tandon et al conducted a study to assess the role of vitamin D deficiency in the development of essential hypertension and aggravation of its vascular complication and observed that serum vitamin D was statistically significantly lower in the hypertensive patient's group than in the control group. Vitamin D is associated with diabetes mellitus as it improves pancreatic β-cell function, decreases insulin resistance, and improves systemic inflammation (Rani, 2014). A retrospective study in South India showed 71.4 percent of the diabetic patients to be vitamin D deficient and 15 percent of the patients to be vitamin D insufficient, suggesting that vitamin D deficiency is highly prevalent among diabetic patients (Basil et al 2013).…”