Vitamin K Deficiency
Vitamin K deficiency is rare in healthy adults because it is readily available in the foods we eat and is made by bacteria that are normally in the large intestines. However, when it does occur, vitamin K deficiency has serious health implications.(1, 4)
- Black, tarry stools
- Bleeding gums
- Blood in urine
- Bruising
- Impaired blood clotting
- Intracranial hemorrhage in babies (VKDB)
- Menorrhagia
- Nosebleeds
Who is at Risk for Vitamin K Deficiency?
Vitamin K deficiency can be caused by certain medications, treatments, or chronic illness, such as:(1, 4, 14)
- Conditions that cause difficulty absorbing nutrients from food (e.g., Crohn's disease, celiac disease, and gallbladder disease).
- Long-term antibiotics, hemodialysis, and IV feeding.
- Blood thinners or some types of cholesterol-lowering drugs.
- Liver disease.
- Diseases that block absorption of dietary fats (e.g., pancreatic disorders, cystic fibrosis).
Vitamin K Deficiency in Infants
Newborn infants who are only breast-fed may have increased risk of vitamin K deficiency for several reasons:(4)
- Not enough vitamin K passes through the placenta to the infant before their born.
- Human milk is relatively low in vitamin K.
- Infant intestines do not have enough of the bacteria that make it and their livers don't store very much of it.
Those babies that are especially at risk include premature infants and/or those born to mothers who took anticonvulsant medication during pregnancy.(1, 4)
Vitamin K: Prevention of VKD Bleeding in Infants with Alpha-1-Antitrypsin Deficiency
Alpha-1 antitrypsin (AAT) deficiency is a genetic disorder that can cause emphysema and liver dysfunction. AAT proteins help protect the cells of different organs. In people who have this disorder, the liver makes misshapen AAT proteins that can't make it to the lung.(18)
Children with AAT deficiency are at risk of developing liver problems. Two of the main functions of the liver are to release bile into the intestines to digest fat and to remove the body's waste products from the blood. Bilirubin is a waste product of red blood cells. If the bile ducts are blocked, the flow of bile and bilirubin to the intestines is blocked. This can cause a liver condition called cholestatic jaundice.(18-20)
Since human breast milk does not contain as much vitamin K as baby formula, infants who are only breastfed are at increased risk of vitamin K deficiency. Cholestatic jaundice and a diet exclusively of human breast milk in babies puts them at greater risk for bleeding in the skull (VKDB). This is a potentially fatal condition.(4, 19)
In one population study conducted in the Netherlands, 40 infants were identified with AAT deficiency. Of the 20 who were exclusively breastfed, 15 developed VKDB, compared to none of the 20 who were fed formula. Regardless of the degree of cholestatic jaundice, the infants in this study had a uniformly high risk of developing VKD bleeding.(19)
The increased risk of VKD bleeding match those noted in another reported study of exclusively breastfed infants with cholestatic jaundice—but with a different underlying condition causing the jaundice. The researchers concluded that regardless of the cause, jaundiced infants who are only breastfed are at high risk of this life-threatening condition without appropriate preventive treatment.(19)
Fortunately VKD bleeding is easy to prevent. The American Academy of Pediatrics and other organizations recommend a prophylactic injection of vitamin K1 be given to all newborns. This would counteract any threat of VKD, including increased risk from a combination of factors.(4)