Vitamin K plays an important role in human life because it performs the essential function of coagulation or blood clotting. Coagulation is the process that helps prevent excessive bleeding inside and outside the body and vitamin K is required to produce the proteins that do the clotting process. One of the most visible signs of vitamin K deficiency is excessive bleeding.

There are two main kinds of vitamin K: vitamin K1 (phylloquinone) that comes from plants, especially leafy green vegetables like spinach and kale, and vitamin K2 (menaquinone) that is produced in the intestinal tract by the body.

Vitamin K is also essential for growing bones and for general health, according to Healthline.

There are five symptoms that an adult with vitamin K deficiency would experience:

1. Easy bruising

If you find bruises on your body that you do not know the cause for, you should get checked for vitamin K deficiency. The bruise might leave and so would your worry about it but it shouldn’t be dismissed casually. 

“It’s common to bump into things, not remember, and see small bruises on your legs or arms,” hematologist Dr. Dana Angelini tells Cleveland Clinic. “However, unprovoked bruises on your torso, back or face are unusual. And that’s a reason to get them checked out.” 

Seniors can also experience more bruising than younger adults since their skin thins with age and there is less fat underneath to cushion the blood vessels.

2. Small blood clots underneath nails

“Your nails are a very good reflection of your health. Many things can occur in the nails that can signify systemic or skin problems,” dermatologist Dr. Christine Poblete-Lopez tells the Cleveland Clinic. 

If you lack vitamin K, you could find small blood clots under your nails. Vitamin K helps combat skin troubles like pigmentation and also works to strengthen your nails against early breakage and yellowing, according to Glam Check.

3. Bleeding in mucous membranes that line areas inside the body

You could experience excessive mucosal bleeding in nose, mouth, gastrointestinal/genitourinary tract, and bruising. Autoimmune diseases like lupus can lead to vitamin K deficiency as well, according to Science Direct. So, if you are experiencing frequent nose bleeds or see a lot of blood when you brush, these could be signs that your body doesn’t have enough vitamin K. 

4. Stool that looks dark black (almost like tar) and contains some blood

Those with vitamin K deficiency could see blood in the urine, blood in the stool, tarry black stools, or extremely heavy menstrual bleeding, according to Oregon State University. However, it is uncommon in adults and infants, while newborns are more prone to it. Though, if you take vitamin K antagonists and individuals with significant liver damage or disease, can have the condition. 

Those with fat malabsorption disorders, including inflammatory bowel disease and cystic fibrosis, may be at increased risk. 

5. Reduced mobility in older adults 

A new study found that older adults with insufficient vitamin K are at a higher risk for mobility disability. The study, Vitamin K Status and Mobility Limitation and Disability in Older Adults: The Health, Aging, and Body Composition Study, published in The Journals of Gerontology, says that they have built on older studies that looked at “slower gait speed and a higher risk of osteoarthritis”. 

They found that older people develop mobility limitation and disability when they have low blood levels of phylloquinone, which comes from consuming green, leafy vegetables.

Vitamin K deficiency in infants

Vitamin K deficiency can be dangerous for newborns and infants. When doctors are looking for signs of deficiency of the vitamin in them they also look for bleeding from the area where the umbilical cord has been removed, bleeding in the skin, nose, gastrointestinal tract, or other areas, bleeding at the penis if the baby has been circumcised, and sudden brain bleeds, which are deemed severe and potentially life-threatening, according to Healthline.