As you probably know (if you paid attention during school geography lessons), folk living in the Northern American and European continents don’t get to enjoy as much sunlight as we do. They have bitterly cold winters where it’s dark even before the working day ends. No-one spends too much time outside from day to day, and when they do, as little skin as possible is exposed to the bitter weather. Researchers studying fertility of women in areas with these long winters have noticed an interesting trend: a spike in conception rates during summer. Coincidentally, this is when everyone gets more sun exposure. Blood tests confirmed that the vitamin D levels of women rose during summer and dipped during winter. Could vitamin D be responsible for this boost in fertility rates?
Curiously, the research done so far around vitamin D and fertility is quite, well, “messy” (to use an unscientific term). There are plenty of studies, but each have utilised different supplement quantities and with sometimes with not enough subjects to reach statistically sound conclusions. Review studies (where all the studies are assessed together) invariably comment that they can’t be sure, for sure, whether vitamin D affects fertility, because the science isn’t strong enough. But at the same time they point to those observations of women’s fertility in the far northern latitudes.
So if you want to know, definitely, that vitamin D boosts fertility, you’ll have to wait while the science develops further. But in the meantime, if your desire is to conceive a baby focus on conceiving consider how much sunlight you are exposed to, whether your workplace has windows, whether you get outside to exercise, and whether your vitamin D levels are sufficient for pregnancy.
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