Vitamin K - All About Vitamin K For Kids

Posted on June 04 2021, By: Dr. Aqsa Ph.D. Scholar in Nutrigenomics

Vitamin K - All About Vitamin K For Kids




Vitamin K belongs to the family of fat-soluble vitamins. There are two forms of vitamin K: menaquinones (vitamin K2) and phylloquinone (vitamin K1). The major type is K1, and it is found in foods like spinach, collard greens, and kale. The other type is K2, which is found in fermented foods and animal products. Vitamin K is also produced naturally by bacteria in your body. (1)

What does vitamin K do? This vitamin helps in making various proteins in the human body that are required for bone building and blood clotting. For example, osteocalcin is a protein in your body that needs vitamin K to make bone tissues. Prothrombin is another vitamin-K-dependent protein that is directly involved in blood clotting. (2)

Vitamin K is used throughout the entire human body, including the pancreas, brain, heart, liver, and bones. This vitamin breaks down quickly and is excreted from the body through stool and urine. Unlike other fat-soluble vitamins, it does not cause toxicity even with high doses in the human body because of this quick breakdown. Deficiency of this vitamin is rare because the foods we eat contain a good amount of K1. However, some health conditions and drugs can interfere with the absorption of this vitamin, causing its deficiency in your body. In case of severe deficiency, supplements can be used to meet the recommended daily amount. (1)

How Does Vitamin K Function in Your Child’s Body?

Vitamin K aids in blood clotting and the prevention of bleeding disorders in children, especially newborns as newborns are often born with a lack of vitamin K. Vitamin K also promotes bone formation in your child. It stimulates the differentiation of osteoblasts (bone cells) by enhancing the level of bone formation markers (such as insulin-like growth factor and alkaline phosphatase) in the body. (2)(3)(4)

Like other fat-soluble vitamins and dietary lipids, vitamin K is absorbed by the enterocytes (intestinal absorptive cells) in the jejunum and ileum of the small intestine. Micelles, active pancreatic enzymes and bile are required for proper absorption of vitamin K. Vitamin K is also produced naturally by bacteria in your small intestine, and vitamin K supplements can even be used when prescribed antibiotics have killed this bacteria in your small intestine. (2)(5)

Why Do Children Need Vitamin K?

No one denies the importance of micronutrients for kids. It is critical to ensure that your child gets an adequate amount of vitamins and minerals for healthy growth and development. Health professionals believe that poor nutrition increases the risk of several diseases, such as bone fractures in older children.

Vitamin K provides several health benefits to your child, including the following: (6)

  • Promotes bone health
  • Supports heart health
  • Helps with blood clotting

Promotes bone health: Research has claimed that vitamin K2 contributes to bone health in children and adults. For example, a study depicted that vitamin K2 levels in healthy girls aged 11 to 12 years are strongly associated with high bone mineral content. (7)

Scientists believe that vitamin K1 and K2 are required for making a molecular modification in a protein known as osteocalcin, which is released from osteoblasts (bone-forming cells). The molecular modification of osteocalcin allows it to bind with calcium and become an integral part of the bone. Physicians now use unmodified osteocalcin levels in the blood as a marker for bone loss and different bone diseases, like osteoporosis.

Another study has demonstrated that vitamin K is essential for childhood bone development. It is non-toxic and safe, even at high doses. It plays a significant role in maintaining a healthy smile by preventing tooth decay in kids. osteocalcin activated by vitamin K2 not only transfers calcium to your bones but also enhances the production of new dentin that is present underneath your tooth enamel. (7)

Supports heart health: An adequate intake of vitamin K in children supports heart health and reduces the risk of heart diseases at a later age. The research has indicated that vitamin K prevents the mineralization of calcium in your arteries, which ultimately decreases the risk of a heart attack.

This vitamin promotes the activation of matrix gla protein in blood vessels. This protein is found in the smooth muscle cells of your arterial walls, and it binds calcium and raises calcium levels in the blood. This process is important for reducing the stiffening of your arterial walls and lowering the risk of hypertension, stroke, lung embolism (blockage of pulmonary arteries), and thrombosis (abnormal blood clotting in your heart’s arteries). Another study has concluded that people who take higher doses of vitamin K have a 52% less risk for developing artery calcification and a 57% less chance of dying due to heart attack. (8)

Helps with blood clotting: Vitamin K plays a promising role in blood clotting and preventing the risk of bleeding disorders in children. This vitamin is required by a protein (prothrombin) that makes a fibrin web in the second part of the clotting process. It is essential for the activation of certain coagulation factors involved in initiating the final clotting process.

In newborn babies, this vitamin is essential to prevent a serious bleeding disorder known as vitamin K deficiency bleeding (VKDB), also called hemorrhagic disease of the newborn (HDN). Your babies do not get enough vitamin K while in utero and when they are breastfeeding. A lack of this vitamin increases the risk of VKDB in newborns. VKDB can cause bleeding in the brain and may result in death. To prevent this problem in newborns, an injection of vitamin K is given to them. By the age of 6 months, your baby can begin building a sufficient supply of vitamin K. (2)(4)(5)

What Are the Symptoms of Low Vitamin K?

Common causes of vitamin K deficiency include inadequate dietary intake, low absorption, and decreased storage due to liver disease. It can also be caused by the low production of vitamin K in your intestine. Health experts claim that newborns are at higher risk for vitamin K deficiency for several reasons: (9)

  • Mother’s milk is deficient in vitamin K
  • Vitamin K does not transfer properly from mother to baby during pregnancy
  • Infant’s liver does not use vitamin K efficiently
  • Newborns cannot produce this vitamin on their own in their first few days of life

The common signs and symptoms of vitamin K deficiency in children include:

  • Easy bruising
  • Blood-thinning
  • Stomach pain
  • Fatigue

Easy bruising:  If your child bruises easily, they might be showing a sign of vitamin K deficiency. Research has revealed that vitamin K deficiency enhances the risk of hemorrhagic diseases in children. This can lead to easy bruising and excessive bleeding, which can be fatal in severe cases. (10)

Blood-thinning:  As discussed above, vitamin K plays a promising role in blood clotting. The research has concluded that children with an adequate amount of vitamin K are not able to stop excessive blood flow, even with minor injuries. A lack of vitamin K can also cause oozing from your child’s gums and nose due to abnormal blood thinning. (10)

Stomach pain:  Health experts believe that vitamin K is essential for facilitating smooth digestion. If you find that your child often complains about stomach pain or other digestive issues, then it might be due to the deficiency of this vitamin or another vital nutrient. (10)

Fatigue:  Lack of vitamin K can lead to anemia in kids because of heavy bleeding, and anemia is widely known to cause fatigue and weakness in children. It also makes them feel tired, lifeless, and appear pale. (10)

How Much Vitamin K Does Your Kid Need per Day?

Dosing recommendations for vitamin K are provided in the Dietary Reference Intake (DRI) developed by the Food and Nutrition Board (FNB). DRI is the optimal amount of nutrients that a person needs per day. (11)

Remember to provide an adequate amount of vitamin K to your children to meet their body’s essential nutritional needs. The recommended dietary allowance (RDA) for this vitamin is provided in micrograms (mcg) below: (12)

Age Recommended daily amount in micrograms (mcg)
7-12 months 2.5 mcg
1-3 years 30 mcg
4-8 years 55 mcg
9-13 years 60 mcg
14-18 years 75 mcg
19+ years 120 mcg (males)/90 mcg (females)

Should You Give Vitamin K Supplements to Your Kid?

Vitamin K injections are given to newborn babies because their bodies do not have an adequate amount of this vitamin. For toddlers, it is preferable to provide vitamin K through a diet or healthy, whole foods. You can also give vitamin K supplements to your children if they do not consume foods rich in this vitamin. It is suggested that you first consult your pediatrician or a health care professional before giving vitamin K supplements to your kid. (9)

Which Foods Contain Vitamin K?

Major dietary sources of vitamin K1 include leafy green vegetables, some fruits, and vegetable oils. Eggs, milk, dairy products, and meat are low in vitamin K1 but high in K2. Cheese and other fermented products are also rich in vitamin K2. The most common dietary sources of this vitamin in the American diet are broccoli, spinach, canola oil, soya bean oil, and iceberg lettuce.

Here are some foods that contain healthy amounts of vitamin K: (2)

 Food Name Serving size Micrograms (mcg) per serving
Natto (fermented soy beans) 3 oz 850 mcg
Green turnips, boiled 1/2 cup 426 mcg
Kale, raw 1 cup 113 mcg
Soy beans, roasted 1/2 cup 43 mcg
Soy bean oil 1 tbsp 25 mcg
Pumpkin, canned 1/2 cup 20 mcg
Okra, raw 1/2 cup 16 mcg
Pine nuts, dried 1 oz 15 mcg
Iceberg lettuce 1 cup 14 mcg
Grapes 1/2 cup 11 mcg
Canola oil 1 tbsp 10 mcg
Figs, dried 1/4 cup 6 mcg

What Are the Side Effects of Taking Vitamin K?

Children and adults do not normally experience side effects when taking vitamin K at recommended amounts per day. On the other hand, some people have reported diarrhea and stomach problems after taking vitamin K supplements.

Vitamin K toxicity is rare in children. A study has depicted that vitamin K1 is not toxic for humans when consumed orally, even in large doses. However, megadoses of vitamin K2 can result in toxicity. The research has revealed that when vitamin K2 toxicity occurs in infants, it exhibits symptoms of jaundice and hyperbilirubinemia. Another study has concluded that vitamin K2 toxicity can lead to kernicterus (brain damage) in children.

Several studies have shown that large doses of vitamin K supplements can cause hemolytic anemia in kids due to its toxic effects on the bone matrix, enzymes of blood clotting, and membrane of red blood cells. It is important to note that people taking warfarin (a blood-thinning drug) should not take vitamin K supplements because it can result in severe side effects. (1)


Vitamin K belongs to the family of fat-soluble vitamins primarily found in leafy green vegetables. It plays a crucial role in blood clotting and bone formation in kids. Vitamin K provides several health benefits to your child, such as supporting bone and heart health. On the other hand, deficiency of this vitamin can result in easy bruising, fatigue, stomach pain, and blood-thinning in children. Because babies do not receive an adequate amount of vitamin K while in utero, vitamin K injections are routinely given to newborns to make up for its lack when they are born. Vitamin K supplements might be given to your child in case of severe deficiency, and it is always recommended that you seek the approval and guidance of your child’s pediatrician before supplementing your child’s diet with additional vitamin K.




Disclaimer: The content of this blog post is intended for informational purposes only. It is not intended as a substitute for professional medical advice, diagnosis, or treatment. You should not use this information for diagnosing or treating a health problem or disease, or prescribing any medication or other treatment. Always seek the advice of your physician or other qualified health provider before taking any medication or nutritional, herbal or homeopathic supplement and with any questions you may have regarding a medical condition.