TY - JOUR
T1 - Genetics, diet, and season are associated with serum 25-hydroxycholecalciferol concentration in a Yup'ik study population from southwestern Alaska
AU - Fohner, Alison E.
AU - Wang, Zhican
AU - Yracheta, Joseph
AU - O'Brien, Diane M.
AU - Hopkins, Scarlett E.
AU - Black, Jynene
AU - Philip, Jacques
AU - Wiener, Howard W.
AU - Tiwari, Hemant K.
AU - Stapleton, Patricia L.
AU - Tsai, Jesse M.
AU - Thornton, Timothy A.
AU - B. Boyer, Bert
AU - Thumme, Kenneth E.
N1 - Publisher Copyright:
© 2016 American Society for Nutrition.
PY - 2016
Y1 - 2016
N2 - Background: Lowblood vitamin D concentration is a concern for people living in circumpolar regions, where sunlight is insufficient for vitamin D synthesis in winter months and the consumption of traditional dietary sources of vitamin D is decreasing. Objective: The objective was to characterize the effects of diet, genetic variation, and season on serum 25-hydroxycholecalciferol [25(OH)D3] concentrations in Yup'ik Alaska Native people living in rural southwest Alaska. Methods: This study was a cross-sectional design that assessed the associations of traditional diet (via a biomarker, the RBC δ15N value), age, gender, body mass index (BMI), community location, and genotype of select single nucleotide polymorphisms (SNPs) in cytochrome P450 family 2, subfamily R, peptide 1 (CYP2R1), 7-dehydrocholesterol reductase (DHCR7), and vitamin D binding protein (GC) with serum 25(OH)D3 concentrations in 743 Yup'ik male and female participants, aged 14-93 y, recruited between September 2009 and December 2013. Results: Yup'ik participants, on average, had adequate concentrations of serum 25 (OH)D3 (31.16 1.0 ng/mL). Variations in diet, BMI, age, gender, season of sample collection, and inland or coastal community geography were all significantly associatedwith serum 25(OH)D3 concentration. In models not adjusting for other covariates, age, diet, and seasonal effects explained 33.7%, 20.7%, and 9.8%, respectively, of variability in serum 25(OH)D3 concentrations. Of the 8 SNPs interrogated in CYP2R1 and DHCR7, only rs11023374 in CYP2R1 was significantly associated with serum 25(OH)D3, explaining 1.5% of variability. The GC haplotype explained an additional 2.8% of variability. Together, age, diet, gender, season of sample collection, BMI, geography of the community, and genotype at rs11023374 explained 52.5% of the variability in serum 25(OH)D3 concentrations. Conclusions: Lower consumption of the traditional diet was associated with lower serum concentrations of 25(OH)D3. Younger adults and youth in this community may be at increased risk of adverse outcomes associated with vitamin D insufficiency compared with older members of the community, especially during seasons of low sunlight exposure, because of lower consumption of dietary sources of vitamin D.
AB - Background: Lowblood vitamin D concentration is a concern for people living in circumpolar regions, where sunlight is insufficient for vitamin D synthesis in winter months and the consumption of traditional dietary sources of vitamin D is decreasing. Objective: The objective was to characterize the effects of diet, genetic variation, and season on serum 25-hydroxycholecalciferol [25(OH)D3] concentrations in Yup'ik Alaska Native people living in rural southwest Alaska. Methods: This study was a cross-sectional design that assessed the associations of traditional diet (via a biomarker, the RBC δ15N value), age, gender, body mass index (BMI), community location, and genotype of select single nucleotide polymorphisms (SNPs) in cytochrome P450 family 2, subfamily R, peptide 1 (CYP2R1), 7-dehydrocholesterol reductase (DHCR7), and vitamin D binding protein (GC) with serum 25(OH)D3 concentrations in 743 Yup'ik male and female participants, aged 14-93 y, recruited between September 2009 and December 2013. Results: Yup'ik participants, on average, had adequate concentrations of serum 25 (OH)D3 (31.16 1.0 ng/mL). Variations in diet, BMI, age, gender, season of sample collection, and inland or coastal community geography were all significantly associatedwith serum 25(OH)D3 concentration. In models not adjusting for other covariates, age, diet, and seasonal effects explained 33.7%, 20.7%, and 9.8%, respectively, of variability in serum 25(OH)D3 concentrations. Of the 8 SNPs interrogated in CYP2R1 and DHCR7, only rs11023374 in CYP2R1 was significantly associated with serum 25(OH)D3, explaining 1.5% of variability. The GC haplotype explained an additional 2.8% of variability. Together, age, diet, gender, season of sample collection, BMI, geography of the community, and genotype at rs11023374 explained 52.5% of the variability in serum 25(OH)D3 concentrations. Conclusions: Lower consumption of the traditional diet was associated with lower serum concentrations of 25(OH)D3. Younger adults and youth in this community may be at increased risk of adverse outcomes associated with vitamin D insufficiency compared with older members of the community, especially during seasons of low sunlight exposure, because of lower consumption of dietary sources of vitamin D.
KW - Alaska Native
KW - American Indian
KW - Cholecalciferol
KW - Polyunsaturated fatty acid
KW - Public health
KW - Vitamin D
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UR - http://www.scopus.com/inward/citedby.url?scp=84959261007&partnerID=8YFLogxK
U2 - 10.3945/jn.115.223388
DO - 10.3945/jn.115.223388
M3 - Article
C2 - 26661839
AN - SCOPUS:84959261007
SN - 0022-3166
VL - 146
SP - 318
EP - 325
JO - Journal of Nutrition
JF - Journal of Nutrition
IS - 2
ER -