NUTRIGENETIC MARKERS OF VITAMIN D DEFICIENCY

FINDING GENETIC MARKERS FROM THE 2013 PHILIPPINE NATIONAL NUTRITION SURVEY USING HIGH-THROUGHPUT NEXT GENERATION SEQUENCING

Abstract

INTRODUCTION
In the Philippines, based on the 2013 National Nutrition Survey, vitamin D deficiency was highest in Benguet at 60.3% and lowest in Cagayan, but still very high, at 19.5%. With vitamin D implicated in a wide range of multiple health outcomes, a fuller understanding of the determinants of vitamin D status is needed and must include consideration of inherited characteristics.

OBJECTIVE
The study determined the relationship of serum vitamin D levels and genetic variations in 502 lifestyle related genes among adult respondents, age 21 years old and above, from the 2013 Philippine National Nutrition Survey (NNS).

METHODOLOGY
The study followed a cross-sectional research design. A total of 1,160 adult respondents of the 2013 NNS and living in Metro Manila, Philippines were included in the study. Anthropometric, biochemical, clinical and dietary data were generated through validated questionnaires, physical examination and laboratory analyses. Total serum 25-hydroxyvitamin D (25OHD3) was determined using electro-chemiluminescence binding assay method. Genomic DNA was used for massively parallel sequencing of 502 lifestyle related genes.

RESULTS
Of the study participants, 56% were classified as having low serum 25OHD3 concentration (<75 nmol/mL). The data discovered at least six genetic variations show statistically significant differences in serum vitamin D concentration across genotypes. These genes were previously known
to have contributed to the risk of developing Type 2 Diabetes Mellitus, Obesity, Iodine Deficiency and a neurodegenerative disorder.

CONCLUSION AND RECOMMENDATION
Large-scale analysis of genes associated with lifestyle disease and other determinants of overall health have shown great utility in the discovery of genes and polymorphisms that play a role in vitamin D nutrition. Post – hoc test may be performed to confirm where the differences occurred between groups. It is envisioned that understanding how genetic variations interact with environmental factors, especially nutrition may hold the key to better prevention and management of nutrition-related diseases and may be basis for future innovative genome-based functional food product development enriched with vitamin D.