Resumen de Vitamin D Receptor Fok-I Polymorphism Modulates Diabetic Host Response to Vitamin D Intake: Need for a nutrigenetic approach
Tirang R. Neyestani, Abolghassem Djazayery, Sakineh Shab-Bidar, Mohammad Reza Eshraghian, Ali Kalayi, Nastaran Shariátzadeh, Niloufar Khalaji, Malihe Zahedirad, A�zam Gharavi, Anahita Houshiarrad, Maryam Chamari, Sepideh Asadzadeh
Abstract OBJECTIVE Interpopulation as well as interindividual variations in response to vitamin D intake commonly observed in subjects with type 2 diabetes may be related to genetic makeup. One of the candidate genes potentially responsible for this diversity is vitamin D receptor (VDR). This study aimed to investigate the interactive effect of VDR Fok-I polymorphism and vitamin D intake on diverse aspects of diabetic host response.
RESEARCH DESIGN AND METHODS Glycemic status, lipid profiles, inflammatory biomarkers, and VDR Fok-I genotypes were determined in diabetic subjects (n = 140) who participated in a randomized controlled trial. Participants consumed two 250-mL bottles per day of yogurt drink (doogh) fortified with 500 IU vitamin D/250 mL for 12 weeks.
RESULTS Mean serum 25(OH)D increased by ~30 nmol/L (P < 0.001). The time × intervention effect was significant for 25(OH)D (P = 0.030), HDL (P = 0.011), high-sensitivity C-reactive protein (hsCRP) (P < 0.001), interleukin (IL)-4 (P = 0.008), and IL-6 (P = 0.017) among the genotypic groups. The alleles were defined as ��F�� or ��f�� depending on the absence or presence of the restriction site, respectively. The least increment in 25(OH)D was in ff (23.0 ± 3.8 nmol/L) compared with Ff (31.2 ± 3.4 nmol/L) and FF (35.6 ± 2.7 nmol/L) (P for trend = 0.009), but only the difference between ff and FF was significant (P = 0.023). FF group had the largest decrement of both hsCRP and IL-6 compared with Ff (P < 0.001 and P = 0.038) and ff (P = 0.010 and P = 0.048), respectively.
CONCLUSIONS We concluded that those of VDR ff genotype may be regarded as �low responders� to vitamin D intake in terms of response of circulating 25(OH)D and certain inflammatory biomarkers. A nutrigenetic approach may, therefore, be needed to protect diabetic patients from vitamin D deficiency.
