For parts of the world, sunshine is coming back, but still not enough to provide for sufficient levels of vitamin D in our bodies. In the world of reproduction, the importance of vitamin D was initially shown in experiments with mice. Mice who are either deficient in vitamin D, or who lack the vitamin D receptor, can demonstrate underdevelopment of the uterus and inability to form normal mature eggs, resulting in infertility. If pregnancy is achieved, the fetuses of these mice show impaired growth. Reproduction is normalized in mice with vitamin D supplementation. In humans, the vitamin D receptor is present in many female organs, including the ovary, uterus, and placenta. The active form of vitamin D, the so called calcitriol has many roles in female reproduction as well as in the #fertilityprotection. Bound to its receptor, calcitriol is able to control the genes involved in making estrogen. The uterine lining produces calcitriol in response to the embryo as it enters the uterine cavity, shortly before implantation. Calcitriol controls several genes involved in embryo implantation. Once a woman becomes pregnant, the uterus and placenta continue to make calcitriol, which helps organise immune cells in the uterus, so that infections can be fought without harming the pregnancy. Poor vitamin D status has been associated with certain pregnancy complications such as gestational hypertension and diabetes.

As vitamin D plays many other positive roles in our bodies, we #inthefertility recommend you make sure your body has enough. You can start with sea fish and fish oil as well as with yolks from eggs from outdoor chicken farming, but you can always try good quality supplements.

One more important note to those TTC and being on the road for some time: vitamin D is associated with depression as those, who were diagnosed with deficiency experience more symptoms of depression than those with only insufficient levels of vitamin D. These people would have been found to be more sad, fatigued, or have more difficulty concentrating than others. They may have also lost enjoyment for things that used to give them pleasure. And that is exactly what you have to avoid. Think of it next time you enjoy a nice walk with your partner, hand in hand, facing the healing of sunshine.