Low selenium status in pregnancy has been associated with hypertension, pre-eclampsia, premature birth, inflammation and adverse glucose and lipid parameters.[1-3]
Selenium is an essential element of numerous enzymes and selenoproteins, and so is involved in many biological roles including antioxidant activity, DNA and thyroid hormone synthesis, muscle function, reproduction and immunity.[4-7]
Factors that influence endogenous selenium levels include intake, gender, age, physical activity, smoking and genotype.[1,5]
The synthesis and functionality of the various selenoproteins is determined by the capacity for gene-level translation, and several polymorphisms potentially influencing selenium status have been identified.[1,7]
The United Kingdom Selenium in PRegnancy INTervention (SPRINT) study recently investigated the impact of several polymorphisms on selenium status during pregnancy.
Healthy primiparous pregnant women were randomly given either 60mg selenium as yeast (n=113) or placebo (n=114) from their initial hospital antenatal appointment (mean gestational age (GA) 12.3 SD 0.9 weeks) until delivery.
All subjects had blood samples taken at baseline and 35 weeks GA and toenail clippings at 16 weeks GA. DNA genotyping was done for dimethylglycine dehydrogenase (DMGDH) variant rs921943, selenoprotein P (SEPP1) variants rs3877899 and rs7579, and glutathione peroxidases cytosolic GPx1 variant rs1050450 and phospholipid GPx4 variant rs713041.
There were significant associations between DMGDH rs921943 and both whole-blood and toenail selenium at 12 weeks GA (p-adjusted=0.03; p=0.04). However, DMGDH rs921943 was not associated with the longitudinal decrease in whole blood selenium between 12-35 weeks GA, with more pronounced declines observed in women with the G allele versus the minor A allele.
Conversely, whole blood selenium from 12-35 weeks GA was significantly associated with the SEPP1 rs3877899 genotype (p=0.005), with less decline observed in carriers of the A allele. This genotype also significantly affected the response of GPx3 to selenium supplementation (p=0.01), with A allele carriers having more elevated increases.
The significance of these polymorphisms on selenium status and pregnancy outcomes requires further investigation.
- Mao J, Vanderlie JJ, Perkins AV, et al. Genetic polymorphisms that affect selenium status and response to selenium supplementation in United Kingdom pregnant women. Am J Clin Nutr 2016;103(1):100-106. [Full Text]
- Rayman MP, Bath SC, Westaway J, et al. Selenium status in UK pregnant women and its relationship with hypertensive conditions of pregnancy. Br J Nutr 2015;113(2):249-258. [Full Text]
- Rayman MP, Wijnen H, Vader H, et al. Maternal selenium status during early gestation and risk for preterm birth. CMAJ 2011;183(5):549-555. [Full Text]
- Rayman MP. Selenium and human health. Lancet 2012;379(9822):1256-1268. [Abstract]
- Thomson CD. Assessment of requirements for selenium and adequacy of selenium status: a review. Eur J Clin Nutr 2004;58:391-402. [Full Text]
- Combs GF, Watts JC, Jackson MI, et al. Determinants of selenium status in healthy adults. Nutr J 2011:10:75. [Full Text]
- Mehdi Y, Hornick JL, Istasse L, et al. Selenium in the environment, metabolism and involvement in body functions. Molecules 2013;18(3):3292- 3311. [Full Text]