Vitamin K2 While Pregnant: Benefits, Risks, and Sources

Pregnant woman

Maintaining optimal levels of vitamin K2 during pregnancy supports fetal bone development, promotes healthy blood clotting, and contributes to overall maternal wellness during childbirth.

Discover the benefits of vitamin K2 for pregnant and lactating women and know the signs and symptoms of vitamin K deficiency.   

What is vitamin K2?

Vitamin K is a fat-soluble vitamin that exists in two primary forms: vitamin K1 (phylloquinone) and vitamin K2 (menaquinone), each playing distinct roles in the body.

While vitamin K1 is predominantly found in plant foods, vitamin K2 can be obtained from certain animal products and fermented foods and is generally considered the more effective form of vitamin K. 

Both vitamins K1 and K2 are involved in the production and activation of blood clotting proteins, also known as coagulation factors. These proteins support healthy circulation and aid the body’s natural healing processes.

In addition to supporting blood clotting, vitamin K2 plays a vital role in maintaining calcium balance by helping direct calcium into bones and teeth. This promotes healthy bone metabolism and helps support the integrity of soft tissues like blood vessels, joints, and tendons.

Watch the video below to learn how nutrient deficiencies can impact fetal growth and development. 

Is it safe to take vitamin K2 while pregnant?

Taking vitamin K2 is considered safe during pregnancy, and most prenatal supplements contain this essential nutrient.

Research published in the Cochrane Library highlights the supportive role of vitamin K2 during pregnancy in promoting healthy vitamin K status at birth and suggests that ensuring adequate levels may help maintain normal clotting function and overall newborn health.1

In addition, a study published in Children found that “The lack of adverse or toxic effects of vitamin K2 makes it the ideal choice for supplementation by pregnant and nursing women.”2

Three benefits of vitamin K2 during pregnancy

Vitamin K2 plays a supportive role in maintaining calcium balance, bone development, and healthy blood clotting, all key processes that contribute to overall maternal wellness and fetal growth.

Here are three benefits of vitamin K2 during pregnancy.

1. Promotes skeletal health   

Vitamin K2 is involved in the activation of matrix Gla proteins (MGPs), a group of proteins that bind to calcium and facilitate its deposition into bone and teeth. 

Without sufficient vitamin K2, the body may have difficulty utilizing calcium efficiently, which can affect skeletal support, bone integrity, and healthy fetal development. 

2. Supports brain development 

Vitamin K2 regulates calcium balance and may play a role in the brain development of the developing child. 

Maintaining healthy maternal blood calcium levels is vital for the central nervous system, including neurotransmitter release, neuronal signaling, and synaptic plasticity, all fundamental aspects of the baby’s brain function.

3. Promotes healthy labor and delivery

Vitamin K2 plays a key role in supporting the production of blood clotting factors, which help support healthy circulation and normal bleeding during and after delivery.

Woman with a bruise

Vitamin K2 deficiency signs 

Pregnancy and lactation are critical periods of heightened energy and nutrient needs to support fetal growth and breast milk production, leaving pregnant and breastfeeding mothers at risk of nutritional deficiencies, including vitamin K.

Here are common symptoms of vitamin K deficiency:

  • Frequent bruising
  • Sensitive gums 
  • Unusual bleeding after minor cuts
  • Dark or discolored stools
  • Heavier-than-usual menstrual flow
Fermented foods

Natural sources of vitamin K2

A study published in Environmental Health and Preventive Medicine reports that fermented foods such as natto, sauerkraut, tempeh, and kefir are some of the most concentrated food sources of vitamin K2.3 

In addition, egg yolks, oily fish, beef liver, chicken, grass-fed butter, and cheeses such as gouda, camembert, and edam also contain vitamin K2, and regularly consuming these food sources can support healthy vitamin K levels.  

Vitamin K1, which is predominantly found in plant foods, including green vegetables, can be converted into vitamin K2 by certain gut bacteria. 

“It’s important to note that the efficiency of this conversion process varies greatly,” explains Dr. Berg. “And relying only on microbial vitamin K2 production to maintain adequate vitamin K status can lead to deficiency.”  

Pregnant woman taking supplements

How much vitamin K2 can you take during pregnancy?

Most health professionals suggest a daily intake of 90 mcg of vitamin K2 during pregnancy and breastfeeding. 

However, individuals with Crohn’s disease or inflammatory bowel disease (IBD) and those taking anti-seizure medication may require larger vitamin K2 doses and should consult a healthcare provider for guidance on appropriate vitamin K intake during pregnancy.  

In addition, vitamin K2 works in combination with vitamin D3 to maintain calcium balance and support bone health, and it’s recommended to take a prenatal supplement that contains both of these fat-soluble vitamins. 

The best ratio of vitamin D3 and K2 is around 1000:10, meaning you should choose a prenatal supplement that contains around 10 mcg of vitamin K2 for each 1000 IU of vitamin D and at least 400 mcg of folic acid to support healthy neural development.  

Pregnant woman and little girl   

Key takeaways

Vitamin K2 is an important nutrient that helps regulate calcium balance and supports blood clotting, contributing to strong bones and cardiovascular health.

Maintaining adequate vitamin K2 levels during pregnancy can promote fetal development and skeletal strength, while also supporting healthy labor and delivery. 

FAQ

1. Can you take vitamin D3 and vitamin K2 while pregnant?

Vitamin D3 and K2 are safe and well-tolerated during pregnancy if taken in recommended dosages.  

These two fat-soluble vitamins work in combination to maintain calcium balance and promote bone development, which is crucial for maternal health and fetal development. 

2. Who should not take vitamin K2?

Certain individuals, such as those with blood clotting concerns, kidney or liver conditions, or those using blood-thinning or anti-seizure medications, are advised to consult a healthcare professional before using vitamin K2 supplements to ensure safety and avoid potential interactions.

3. Does vitamin K2 cross the placenta?

Although vitamin K2 has been found to cross the placenta, it’s thought that only small amounts of vitamin K can enter the fetal circulation. 

This may contribute to lower vitamin K levels in newborns, which is why vitamin K2 is often administered under medical guidance shortly after birth to reduce the risk of vitamin K deficiency bleeding (VKDB).

4. Do prenatals have K2?

Many prenatal supplements include vitamin K, but most provide vitamin K1, which mainly supports blood clotting and offers limited support for calcium balance and bone health. Vitamin K2, on the other hand, plays a key role in regulating calcium deposition in the skeleton and supporting fetal bone development.

If you’re considering vitamin K2 during pregnancy, it’s best to consult a healthcare provider to choose the most suitable prenatal supplement.

5. Is vitamin K2 safe during pregnancy?

Yes, vitamin K2 is considered safe during pregnancy and has not been found to cause adverse health effects or toxicity when taken in recommended dosages. 

6. Why is vitamin K2 important in pregnancy?

Vitamin K2 supports healthy fetal bone development by helping regulate calcium balance and also plays a role in blood clotting, which is important during pregnancy and childbirth. 

7. How much vitamin K2 should I take while pregnant?

It’s recommended that pregnant women take 90 mcg of vitamin K2 daily to maintain healthy vitamin K status. 

8. What are the risks of taking too much vitamin K2 during pregnancy?

Taking excessive amounts of vitamin K2 during pregnancy may increase the risk of side effects, and it’s important to follow recommended guidelines and consult a healthcare provider before use. 

9. What are the best natural sources of vitamin K2 for pregnant women?

Some of the best natural vitamin K2 sources include egg yolks, oily fish, butter, cheese, organ meats, and fermented foods such as sauerkraut, kimchi, kefir, and natto, a Japanese soybean dish. 

Sources

  1. https://pmc.ncbi.nlm.nih.gov/articles/PMC6481496/ ?
  2. https://www.mdpi.com/2227-9067/9/1/78 ?
  3. https://pmc.ncbi.nlm.nih.gov/articles/PMC6492326/ ?