We have seen much speculation over the interrelationship of thyroid hormones and B12. A paper discussing exactly that seemed to have much potential. Though have to say, I am still scratching my head about the real meaning of this paper.
Nonetheless, in case someone can interpret it for us, and simply to confirm that there really is something to investigate, here is the abstract:
J Clin Endocrinol Metab. 2017 Sep 5. doi: 10.1210/jc.2017-01362. [Epub ahead of print]
association of thyroid function with maternal and neonatal homocysteine concentrations.
Barjaktarovic M1,2,3, Steegers EAP4, Jaddoe VWV1,5, de Rijke YB3,5, Visser TJ2,3, Korevaar TIM1,2,3, Peeters RP2,3.
1 The Generation R Study Group.
2 Internal Medicine.
3 Academic Center for Thyroid Diseases.
4 Obstetrics and Gynecology.
High homocysteine concentrations are associated with maternal pregnancy complications and low birth weight, jaundice and cerebrovascular accidents in neonates. Thyroid hormone may interfere with homocysteine metabolism via stimulation of vitamin B12- and folate-dependent processes and via effects on enzymes of the re-methylation pathway.
Investigating the associations of maternal and neonatal thyroid function with homocysteine during pregnancy and after delivery, respectively.
Design, setting and participants:
Within Generation R study, a population-based prospective cohort, we studied the associations of maternal and neonatal TSH and FT4 with homocysteine, folate and vitamin B12 concentrations using multiple linear regression analyses.
Main outcome measures:
Thyroid stimulating hormone (TSH), free thyroxine (FT4), homocysteine, folate and vitamin B12 concentrations were determined in early pregnancy (<18 weeks; N=1094 women without folic acid supplementation) and in cord blood of 4475 neonates.
In neonates, there was a positive association of FT4 with homocysteine and an inverse association of TSH with homocysteine. The latter associations attenuated after adjustment for folate and vitamin B12 concentration (β change: for FT4 0.00559 ±0.001, P<0.0001 to 0.00310 ±0.001, P=0.015; and for TSH -0.00165 ±0.001, P=0.005 to -0.00086 ±0.001, P=0.11). In mothers, there was a positive association of FT4 with homocysteine (P=0.026) but no association of FT4 with folate or vitamin B12 (P≥0.08).
Higher thyroid function is associated with higher homocysteine concentrations in pregnant women and in neonates. These data provide new insights into the effects of thyroid hormone on folate and vitamin B12-dependent processes during early growth and development.
Full paper, as so often, behind a paywall.