Learn how vitamin K strengthens bones, protects arteries, and prevents liver and prostate cancer and other degenerative diseases.
Unlike many other nutrients, vitamin K did not receive much attention in the
past. New research, however, indicates that this vitamin is one of the
most amazing anti-aging nutrients available to us. An ongoing scientific
research suggests that vitamin K may play a significant role in
preventing certain cancers and the Alzheimer's disease.
What is vitamin K?
Vitamin K is a group of fat-soluble vitamins that can be found in nature and
made in the body. Phylloquinone, or vitamin K1, is the natural form of
vitamin K that is found in plants such as dark green leafy vegetables,
alfalfa, and kelp. Menaquinone, or vitamin K2, is the vitamin K produced
by the bacteria in our intestines. Menadione, or vitamin K3, is a
synthetic compound that has the chemical structure of the natural
vitamin K. This form of vitamin K, however, is regarded as toxic because
it generates free radicals.
Vitamin K was discovered
in 1929 by a Danish researcher Henrik Dam. He noticed that chicken that
were fed a fat-free diet were susceptible to hemorrhage. Moreover, blood
taken from these birds coagulated very slowly. Intrigued by this
observation, he investigated this strange phenomena and found out that a
particular substance was necessary for the blood to coagulate. The
chickens in his experiment lacked it because that substance was found
only in the fatty foods. He named that substance "coagulation vitamin"
using the German spelling, hence the name vitamin K.
Vitamin K is easily destroyed by extreme heat, light, alkaline substances, strong acids, radiation, and oxidizing agents. Some research, however, shows that cooking does not significantly diminish vitamin K content in vegetables.
Vitamin K is easily destroyed by extreme heat, light, alkaline substances, strong acids, radiation, and oxidizing agents. Some research, however, shows that cooking does not significantly diminish vitamin K content in vegetables.
Vitamin K is absorbed from the upper small
intestine with the help of bile salts and pancreatic juices and carried
to the liver where it is utilized in the synthesis of prothrombin - a
key blood clotting factor in the body. Vitamin K is stored in small
doses within the body. The highest concentrations are found in the
liver, the pancreas, and in the bones. Any excess of this vitamin is
excreted. High intake of vitamin E and calcium interferes with the
absorption of vitamin K.
Functions of vitamin K
- The most important and best studied function of vitamin K is it role in the blood clotting process. Vitamin K is required for the synthesis of the coagulating factors, mostly the blood-clotting protein prothrombin.
- Vitamin K protects the heart because it prevents the calcification of the aorta and the heart valves.
- Vitamin K is responsible for bone health. Low serum levels of vitamin K are normally associated with lower bone mineral density and indicate an increased risk of hip fracture. Supplementation with vitamin K may improve bone mass in postmenopausal women. Research shows that when vitamin K is taken together with vitamin D3, it can prevent osteoporosis.
- Vitamin K regulates calcium levels in the body. I helps keep calcium in the bones and out of the arteries. Scientists suggest that by regulating calcium, vitamin K may reverse hypertension and reduce the susceptibility to stroke.
- Research shows that vitamin K has the potential to reduce inflammation in the body by inhibiting interleukin-6, a substance that affects the immune system and is responsible for the inflammatory processes in the body.
- According to the latest research conducted in Japan, vitamin K may be involved in blood sugar control. Pancreas has very high concentrations of vitamin K and researchers discovered that this vitamin has some effects on insulin and glucose concentrations in the body. Laboratory tests showed that insufficient levels of vitamin K in the body interfere with the clearance of glucose causing release of too much insulin. This discovery may be of great importance in diabetes prevention and treatment.
- Studies demonstrated that vitamin K is a powerful antioxidant. It fights free radicals in the liver and protects linoleic acid from oxidation. It may be useful in preventing liver cancer. Research conducted in Germany also shows that vitamin K may prevent prostate cancer.
- Vitamin K supports the brain and the nervous system. Scientists discovered that vitamin K is required for the synthesis of the fats called sphingolipids that are critical in the formation of the myelin sheath - an outer wrapping around the nerves. This discovery may be useful in the treatment and prevention of Alzheimer's disease.
Nutritional sources of vitamin K
Most
dietary vitamin K come from vegetable especially from dark leafy greens
such as kale, chard, and collards and from cruciferous vegetables such
as broccoli, Brussels sprouts, and cabbage. Blackstrap molasses,
fermented soy products, and polyunsaturated oils also contain
significant amounts of vitamin K. Vitamin K is also found in egg yolks,
cow liver, fish liver, yogurt, and Swiss cheese.
Deficiency
Deficiency
of vitamin K is very rare and is associated with impaired absorption
rather than with inadequate diet. Deficiency occurs when the body
cannot absorb this vitamin from the intestines or when the intestinal
flora has been destroyed by prolonged treatment with antibiotics.
People suffering from cystic fibrosis, celiac disease, and cholestasis
may become deficient. Symptoms of vitamin K deficiency usually include
tendency to bruises, nose bleeding, gastrointestinal bleeding, gum
bleeding, and heavy and prolonged menstrual bleeding.
Recommended daily dose
The
recommended dietary allowance (RDA) for vitamin K is 80 µg per day for
adult men and 65 µg per day for adult women. No more than 50 µg per
day may be administered to the newborn babies to prevent hemorrhage.
A healthy, balanced diet usually provides 75 - 150 µg of vitamin K in its natural, bio-available form.
Warning
Although
there is no known toxicity associated with high doses of the naturally
occurring vitamin K1, synthetic forms of this vitamin should be
avoided. High intake of vitamin K is not recommended for individuals
taking anticoagulant medications such as Warfarin. Their diet should
not contain more than 120 µg of this vitamin.
By Dominique Allmon
*This information is for educational purpose only. It is not meant to diagnose, treat or cure a disease.
Vitamin K - An Extraordinary Anti-Aging Nutrient by Dominique Allmon is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.