One of the most known changes made by women who are pregnant or planning to be pregnant is their diet. After all, when everything you eat is going towards a new life, every bite of food is incredibly important. Pregnancy—even the first few weeks, when conception might go unnoticed— demands a large amount of a wide range of vitamins and nutrients for the mother and the baby. Among these, vitamins D3 and K2 are especially important for supporting both the mother and baby’s bone and skeletal health before, during, and after pregnancy.
Throughout pregnancy, calcium is transferred from the mother’s bone to the developing fetus, to ensure that the baby has enough calcium to support proper skeletal development and bone strength. In response to the increased calcium demand, the mother’s body is adjusting to protect her calcium supply and hopefully prevent bone disorders, such as osteoporosis. These include changes to hormone levels, calcium absorption from foods, and calcium metabolism.
What is Vitamin D3?
Vitamin D3 is a fat-soluble vitamin that can be found in fatty fish (tuna, salmon, trout), egg yolks, and dairy products; it is also naturally produced when your skin is exposed to sunlight. Vitamin D plays a particularly vital role in female fertility and throughout pregnancy, supporting both the mother’s and baby’s health in multiple ways:
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Enhances calcium absorption in the intestines
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Maintains adequate calcium levels in the blood
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Supports mood regulation and may play a role in serotonin production
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Strengthens the immune system, helping the body fight infections, viruses, and other illnesses
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Supports fetal brain development and promotes cognitive function.
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Linked to improved fertility outcomes, with studies suggesting that optimal vitamin D levels can improve success rates in IVF and frozen donor egg embryo transfers
What is Vitamin K2?
Vitamin K2 is another fat-soluble vitamin. Although vitamin K is less well known compared to vitamin D, vitamin K has many benefits for supporting bone and heart health. Sources of vitamin K2 come from fermented foods (natto, sauerkraut, miso), chicken breast, and our gut microbiome since Vitamin K2 is synthesized by good bacteria. Here is how vitamin K2 plays an important role in pregnancy and fetal development:
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Supports blood clotting by producing proteins that control bleeding and wound healing, which is essential during labor and postpartum recovery.
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Helps regulate calcium by working alongside vitamin D, directing it into bones and away from soft tissues like the arteries.
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Boosts bone density and may help reduce the risk of osteoporosis after pregnancy.
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Supports cardiovascular health for both the mother and baby.
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Supports bone and skeletal development in the growing baby and helps preserve the mother’s skeletal strength and maintain bone density.
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Prevents Vitamin K deficiency bleeding (VKDB) in newborns.
Since Vitamin D3 and K2 work closely together to metabolize calcium, many supplements combine both vitamins to maximize their benefits during preconception, pregnancy, and postnatal periods. Supporting adequate levels of these nutrients support female reproductive health and promote strong bone development in the baby while protecting the mother’s bone health, making them essential components of a well-rounded prenatal nutrition plan.
