We don’t hear too much about vitamin K for kids, but it’s an important nutrient health. Vitamin K is a fat-soluble vitamin that plays a starring role in blood clotting.
Vitamin K is important, as it helps bleeding stop. In fact, it is responsible for producing 4 of the 13 proteins required for blood clotting. Read more about the proteins here.
It also helps make other proteins in the body that are important for blood, bone and kidney health. Research indicates that low levels in the blood are associated with low bone density in adults.
Since childhood is the “bone building” period of life, it makes sense to pay attention to this nutrient.
Additionally, like vitamin D, our bodies can produce vitamin K on its own. We make it from certain bacteria in our gut, or digestive system.
Prolonged or frequent use of antibiotics may destroy vitamin K in the gut, so we also rely on vitamin K food sources to make sure we get enough.
Why Newborns Need a Vitamin K Shot
When babies are born, they need a vitamin K shot. This is because they don’t have enough vitamin K in their body to properly clot blood.
Without this supplement, babies are at risk for a bleeding condition called Vitamin K Deficient Bleeding (VKDB), which can cause bruising and excessive bleeding in all the organs.
Babies are at risk for this condition during the first 6 months of life because most of this vitamin is made in our bodies from food and from the bacteria in our gut. Generally, babies aren’t eating food until age 6 months. (And nursing moms don’t pass enough in their breast milk.)
Why a vitamin K shot, you might wonder? The shot is more effective at preventing brain bleeding and the oral version isn’t available in the U.S.
What is vitamin K1 and vitamin K2?
Vitamin K is a term that includes a group of compounds, as I mentioned. The two most important are vitamin K1 and vitamin K2. Vitamin K1 is found in dark, leafy green vegetables.
Vitamin K2 is found mostly in meats, cheeses and eggs, and it’s the type created from bacteria.
Supplements of this nutrient are typically in the form of vitamin K1.
How Much Do Kids Need?
The levels for optimal vitamin K intake are set as Adequate Intakes (AI).
No adverse effects have been reported for intakes above the AI, and there is no Tolerable Upper Intake Level (UL) established, however, avoiding excessive intake (ie, from supplements) is advised.
Adequate Intakes for Children:
0-6 months: 2.0 micrograms/day
7-12 months: 2.5 micrograms/day
1-3 years: 30 micrograms/day
4-8 years: 55 micrograms/day
Boys & Girls, 9-13 years: 60 micrograms/day
Boys & Girls, 14-18 years: 75 micrograms/day
*Adapted from the Institute of Medicine Dietary Reference Intakes
Vitamin K Rich Foods
Collards, spinach and dark salad greens are the highest food sources, with broccoli, Brussels sprouts, cabbage and bib lettuce containing moderate amounts.
Plant oils (soybean, canola, olive, corn) and margarine are also good sources. Can you imagine sautéing collard greens or spinach in canola oil?
What If Your Child Doesn’t Get Enough?
Vitamin K deficiency is extremely rare in the general healthy population; those who are deficient tend to have problems with their intestinal function or have taken medications known to interfere with its metabolism.
The Take-Away Message:
It is unlikely that your child, if healthy, will experience a deficiency of this nutrient.
A diet including green leafy vegetables and plant oils are your best bet for getting enough so your child maintains normal blood clotting and bone health.
Do you need extra from a supplement? Probably not.
If you do use a multivitamin supplement, will it be excessive? Probably not.
Written by: Jill Castle, MS, RDN
Published on: May 11, 2011
Updated on: October 6, 2019