Vitamin K is obtained both from plant food and animal food. Vitamin K can be obtained either from food, or through its synthesis in the intestines of our body. Vitamin K found in plant food is called phylloquinone. In animal food it is found as menaquinone. The bacteria in the intestine can also produce vitamin K.
Inadequacy of vitamin K in the food or the destruction of intestinal bacteria can result in its deficiency. Intake of certain antibiotics can destroy the bacteria that aids in the synthesis of vitamin K. consuming salicylates or aspirin blocks vitamin K.
This deficiency might occur in people of all age group, but is more common in infants. The content of vitamin K in breast milk is very low. Hence, the causes of vitamin K deficiency in children are due to the lack of the vitamin in breast milk and also due to sterile intestines in the infant. Breast milk supplies only about 20% of the requirement. Any deficiency of vitamin K causes hemorrhagic disease in the newborns. There is spontaneous bleeding under the skin or elsewhere, due to this disease. Sometimes the bleeding might take place in the brain, and can cause death, ultimately.
In children it might lead to certain abnormalities like flat nasal bridge, short noses and shortened fingers. In adults, deficiency of vitamin K is rare. It is mostly found in people, who suffer from mal absorption of fats from dietary sources.
The bone protein osteocalcium, when undergoing carboxylation with calcium requires vitamin K. hence, its deficiency results in diseases like osteopenia and osteoporosis. Osteoporosis is a disease in which the bones become weak and are liable to be broken. There might be a risk of hip fracture in older people.
Being a vitamin that aids in blood clotting, the deficiency of vitamin K leads to excessive bleeding. The blood clotting protein prothrombin becomes less active with the deficiency in vitamin K. Excessive bleeding might also result in death.
Vitamin K deficiency results in health problems related to excessive bleeding like heavy menstrual bleeding, bleeding in the stomach and intestine, nose bleeding and hemorrhaging. Bleeding in the genitourinary tract leads to blood in the urine. The deficiency also leads to excessive calcium in the urine called Hypercalciuria.
People deficient in vitamin K have to be fed on food items rich in vitamin K. Green leafy vegetables, oils, olive oil, soybean oil, peas, beans, cow milk, spinach, cabbage and broccoli are some of the food items that contain vitamin K.
In infants, deficiency of vitamin K is treated and prevented with injectables whereas for adults oral doses are recommended. The RDA for an adult is 70-80 mg/day and for infants it is 5 mg/day.