Vitamins A, B, C, D, E & K
Vitamin C is a vitamin. Some animals can make their own vitamin C, but people must get this vitamin from food and other sources. Good sources of vitamin C are fresh
fruits and vegetables, especially citrus fruits. Vitamin C can also be made in a laboratory.
Most experts recommend getting vitamin C from a diet high in fruits and vegetables rather than taking supplements. Fresh-squeezed orange juice or fresh-frozen concentrate is a better pick than ready-to-drink orange juice. The fresh juice contains more active vitamin C. Drink fresh-frozen orange juice within one week after reconstituting it for the most benefit. It you prefer ready-to-drink orange juice, buy it 3 to 4 weeks before the expiration date, and drink it within one week of opening.
Historically, vitamin C was used for preventing and treating scurvy. Scurvy is now relatively rare, but it was once common among sailors, pirates, and others who spent long periods of time onboard ships. When the voyages lasted longer than the supply of fruits and vegetables, the sailors began to suffer from vitamin C deficiency, which led to scurvy.
These days, vitamin C is used most often for preventing and treating the common cold
. Some people use it for other infections including gum disease, acne and other skin infections,
bronchitis, human immunodeficiency virus (HIV) disease, stomach ulcers caused by bacteria called
disease, physical and mental stress, fatigue, and attention deficit-hyperactivity disorder (ADHD).
Other uses include increasing the absorption of iron from foods and correcting a protein imbalance in certain newborns (tyrosinemia).
There is some thought that vitamin C might help the heart and blood vessels. It is used for hardening of the arteries, preventing clots in veins and arteries,
Vitamin D is a vitamin. It can be found in small amounts in a few foods, including fatty fish such as herring, mackerel, sardines and tuna. To make vitamin D more available, it is added to dairy products, juices, and cereals that are then said to be “fortified with vitamin D.” But most vitamin D – 80% to 90% of what the body gets – is obtained through exposure to sunlight. Vitamin D can also be made in the laboratory as medicine.
Vitamin D is used for preventing and treating rickets, a disease that is caused by not having enough vitamin D (
). Vitamin D is also used for treating weak bones (
), bone pain (osteomalacia), bone loss in people with a condition called hyperparathyroidism, and an inherited disease (
) in which the bones are especially brittle and easily broken. It is also used for preventing falls and
in people at risk for osteoporosis, and preventing low
and bone loss (renal osteodystrophy) in people with
Vitamin D is used for conditions of the heart and blood vessels, including
. It is also used for
, muscle weakness,
, chronic obstructive pulmonary disease (COPD),
and gum disease.
Some people use vitamin D for skin conditions including
, actinic keratosis, and lupus vulgaris.
It is also used for boosting the immune system, preventing
, and preventing
Because vitamin D is involved in regulating the levels of minerals such as phosphorous and calcium, it is used for conditions caused by low levels of phosphorous (
and Fanconi syndrome) and low levels of calcium (
Vitamin D in forms known as calcitriol or
is applied directly to the skin for a particular type of psoriasis.
Vitamin E is a vitamin that dissolves in fat. It is found in many foods including vegetable oils, cereals, meat, poultry, eggs, fruits, vegetables, and wheat germ oil. It is also available as a supplement.
Vitamin E is used for treating vitamin E deficiency, which is rare, but can occur in people with certain genetic disorders and in very low-weight premature infants.
Some people use vitamin E for treating and preventing diseases of the heart and blood vessels including hardening of the arteries,
, leg pain due to blocked arteries, and
Vitamin E is also used for
and its complications. It is used for preventing cancer, particularly lung and
and polyps; and gastric,
Some people use vitamin E for diseases of the brain and
including Alzheimer’s disease and other dementias, Parkinson’s disease, night cramps,
, and for epilepsy, along with other
. Vitamin E is also used for Huntington’s chorea, and other disorders involving nerves and muscles.
Women use vitamin E for preventing complications in late
due to high
(PMS), painful periods, menopausal syndrome,
, and breast cysts.
Sometimes vitamin E is used to lessen the harmful effects of medical treatments such as dialysis and
. It is also used to reduce unwanted side effects of drugs such as
in people taking
and lung damage in people taking
Vitamin E is sometimes used for improving physical endurance, increasing energy, reducing muscle damage after
, and improving muscle strength.
Vitamin E is also used for
, asthma, respiratory infections, skin disorders, aging skin, sunburns,
, for certain inherited diseases and to prevent
Some people apply vitamin E to their skin to keep it from aging and to protect against the skin effects of chemicals used for cancer therapy (chemotherapy).
The American Heart Association recommends obtaining antioxidants, including vitamin E, by eating a well-
high in fruits, vegetables, and whole grains rather than from
until more is known about the risks and benefits of taking supplements.
How does it work?Vitamin
E is an important vitamin required for the proper function of many
organs in the body. It is also an antioxidant. This means it helps to
slow down processes that damage cells.
Vitamin K is VITAL to the blood clotting process that stops you bleeding to death from injury. It helps to prevent fractures and has been linked to protective effects against coronary heart disease and some types of cancer. It may have a role to play in the brain and cognitive health.
Keep reading if you care about
Vitamin K shares a number of similarities with vitamin D. Both substances are fat-soluble. Like vitamin D, vitamin K is important for bone health. Also like vitamin D, vitamin K has been studied for almost a century in relation to one particular area of health (blood clotting), while recent studies have suggested a much wider role in the body.
Some people confuse vitamin K with potassium, because the chemical symbol for potassium on the periodic table is K. These are NOT the same substances and have very different effects in the body.
I will show you why your mother was right about eating greens – they really are good for you – and why eating the whole animal makes sense from both a vitamin K perspective and evolutionary perspective…. Organ meats, anyone? Yummy.
The detailed version starts below, if you are in a hurry, you can skip all the science stuff if you want and go straight to the recommendations part, which will be marked like this
BUT that would be boring and you won’t learn much.
For those sticking with me, let’s get to it.
First, some science background.
What is Vitamin K
Vitamin K is best known for its crucial role in blood clotting. Its name actually comes from the German ‘Koagulationsvitamin’, or ‘coagulation vitamin’, although vitamin K plays a role in anticoagulation and many other physiological functions as well.
Vitamin K is a fat-soluble vitamin, along with vitamins A, D, and E. Vitamin K is not one substance but rather a group of compounds with a similar chemical structure. The two naturally occurring forms identified so far are vitamin K and K and both are biologically active in animals and humans.
Vitamin K is found in green plants, where it plays a role in photosynthesis.
Vitamin K is primarily made by bacteria.
Synthetic forms such as vitamin K are toxic and to be avoided.
Babies derive vitamin K and K from their mothers’ milk (or from formula if you are unlucky).
Completely random side-note.
Whenever I hear the word K2 I can’t help but envisage the MOUNTAIN of the same name in the Himalayas.
Famous for being the second highest mountain in the world and also the second deadliest taker of lives (as big mountains go), this thing is a beast and is considered one of the world’s most difficult summits to climb. Two movies about it I remember are K and Vertical Limit, but I digress.
Vitamin K and K are necessary for an important chemical process called carboxylation that allows certain important proteins to function properly. Without vitamin K, these Gla proteins, also known as vitamin K-dependent proteins, would not be able to bind calcium and interact with cell membranes.
Frequently referred to with a traffic light analogy, after speaking about it with my sister, we decided that perhaps the best analogy was your local postal system.
Think of the postal system. Without stamps (calcium), chances are the envelopes and parcels (Gla proteins) in the mail won’t reach their destinations (tissues throughout the body). When mail doesn’t get delivered, especially crucial mail, life can suck.
The good folks at the Postal Service put the correct stamps in the correct place at the correct time in the correct amount on your mail, ensuring that the system works well (this is the role of vitamin K and associated enzymes).
Vitamin K-dependent proteins play important roles in tissues throughout the body.
Their function is still being understood and is a growth area in science – my bet: vitamin K and K will have many surprises in store for us yet as the science evolves.
Hemostasis is the first stage in wound healing and causes bleeding to stop via the blood clotting cascade. Vitamin K (especially K) is essential to this process.
Drugs prescribed to prevent thrombosis such as warfarin act by blocking the action of vitamin K in all in forms. Warfarin decreases the concentration of vitamin K in body tissues and results in clotting factors with inadequate Gla. People taking warfarin or other vitamin K antagonists need to be especially careful and consistent with their vitamin K intake – please consult your doctor if you are on these medications.
A severe vitamin K deficiency results in bruising and bleeding. It is very rare in adults, but can sometimes occur in newborn babies. This is because vitamin K and K are not easily transported across the placenta and the baby’s intestines have not yet been colonized with vitamin K -synthesizing bacteria. Some pediatricians recommend supplementation with vitamin K for newborns, either orally or through an intramuscular injection. However this is a controversial practice because some studies suggested a correlation between newborn vitamin K supplementation and childhood cancers such as leukemia, although a causal link has not been substantiated.
Geek box: the vitamin K-dependent blood clotting cascade proteins carboxylated in the liver are coagulation factors II (prothrombin), VII, IX, and X, and anticoagulant proteins C, S, and Z.
Studies show that vitamin K has a protective effect against bone fractures and that osteoporosis is associated with low levels of vitamin K.
Vitamin K may be more important than vitamin K in this regard, although some studies show also a beneficial effect of vitamin K on bone health:
There is inconsistent evidence on vitamin K’s effect on bone mineral density. Some scientists suggest that vitamin K mediates its skeletal effects through other mechanisms, perhaps through collagen metabolism.
Some of you have asked me about the interaction between vitamin K and vitamin D.
Both are important for bone health. For example, vitamin D’s active form, calcitriol, regulates the synthesis of a protein called osteocalcin, but vitamin K activates this protein into a form that can bind calcium. The two vitamins also appear to have a synergistic effect. A clinical study showed that healthy women who took combined vitamin K, vitamin D and calcium supplements showed greater increases in wrist bone mineral density than the women who took vitamin K only or vitamin D and calcium without vitamin K.
Want good bones, you don’t just need good Vitamin D status, you need to get some Vitamin K action.
Some nutritionists suggest that potential toxic effects of very high vitamin D consumption are in fact only due to vitamin K deficiency, and therefore they advocate co-supplementation as a way to increase total vitamin D intake to higher levels. There is no rigorous evidence to support the safety of this approach.
A build-up of calcium (calcification) in the arterial walls decreases their elasticity and increases the risk of clot formation. In atherosclerosis (hardening of the arteries), calcification of the atherosclerotic plaque occurs at a late stage of the disease.
Vitamin K helps to prevent a build-up of calcium in the arteries. A number of large, prospective cohort studies have shown that intake of K (but not K) is associated with reduced risk of coronary heart disease and a protective effect against calcification of the coronary and aortic arteries. Vascular calcification is a potential side effect of taking vitamin K-antagonists such as warfarin.
Vitamin K may have an effect on cell growth through the vitamin K-dependent growth specific gene 6 protein, or Gas6, which promotes cell survival and inhibits cell death. Gas6 protein binds and activates receptor tyrosine kinases, enzymes that can stimulate cell replication and transformation.
In cancer cell lines in vitro, vitamin K has the opposite effect and inhibits cell growth. Prospective studies in humans suggest that dietary intake of K (but not K) is associated with a reduced risk of prostate and lung cancer. However, rigorous clinical trials are needed to explore the potential effects of vitamin K on cancer.
Central Nervous System
It is possible that vitamin K in all its forms affects cognitive health via the carboxylation of proteins involved in the brain and nervous system. Vitamin K is involved in the biosynthesis of sphingolipids. These complex lipids are a structural component of cell membranes throughout the body and also play a role in cell signalling. They are present in high concentrations in neuronal and glial cell membranes in the brain. Two other vitamin K-dependent proteins are relevant here. Gas6 protein is involved in cell signalling in both the central and peripheral nervous systems and the anticoagulation protein S is expressed in the brain.
Studies in rats suggest that vitamin K and K may trigger gene expression of alkaline phosphatase in gut epithelial cells.
By now you should have figured out that vitamin K and K can be obtained from the diet, and that our own bodies can make K from K. The bacteria living in our gut can also provide us with K (as shown by vitamin K deficiency in people taking antibiotics). Both forms of vitamin K are transported around the blood by lipoproteins.
Vitamin K in both forms can be reused in the body because it undergoes a cycle of oxidation and reduction (the vitamin K cycle). However, it is also extensively metabolized in the liver and excreted in the urine and in feces (in bile), which means that vitamin K levels need to be continually replenished. Vitamin K is the major circulating form of vitamin K and vitamin K is the major form stored in the human liver. Vitamin K has a longer half life.
As outlined above, the two forms of vitamin K appear to have different physiological actions. Vitamin K is preferentially used up by the liver in the synthesis of active blood clotting factors, which may explain its low stores in the liver. Vitamin K is linked with skeletal and cardiovascular health.
Symptoms of deficiency include bleeding (including the gums and gut), heavy menstruation, and bruising. Severe deficiency results in low levels of carboxylated blood clotting factors and can lead to uncontrolled bleeding (hemorrhage).
If you’re worried, have a blood test. High serum levels of under-carboxylated prothrombin (coagulation factor II) can indicate sub-clinical vitamin K deficiency. Remember the postal analogy? This is like finding lots of mail without stamps.
Severe deficiency is very rare. People with the following conditions may be at risk of a sub-clinical vitamin K deficiency:
Newborn infants have a higher risk of vitamin K deficiency.
Drugs can affect vitamin K and K levels in your body. For example, taking antibiotics is associated with low levels. Conversely, large, sudden increases or decreases in vitamin K or K intake can alter the effectiveness of warfarin and other anti-thrombotics.
If you have any of these medical conditions or are on medication, PLEASE seek your doctor’s advice before taking vitamin K supplements or increasing your dietary intake.
Kiwi, I GET IT. Vitamin K IS Important – But what should I DO?
Clearly, vitamin K is important for the health of our blood, artery walls, and bones.
And vitamin K is likely to have a host of other physiological effects not yet elucidated by science.
No question, food is first, and food is best. I advocate consuming vitamin K in both of its forms through your DIET wherever possible.
Tip: remember that the bio-availability of vitamin K is improved by eating fats and by adequate bile synthesis and fat absorption in the gut. Take down some olive oil with that salad.
Strategically optimize your dietary intake of both K and K as they appear to have different effects in the body:
For vitamin K and blood health:
For vitamin K and bone and arterial health:
What Dose Is Best, Kiwi?
In 2001, the non-governmental organization the Institute of Medicine published Adequate Intake (AI) recommendations for vitamin K of 120 mcg/day for men and 90 mcg/day for women.
You can safely consume more than this in the diet if you want to, because no cases of vitamin K toxicity have ever been reported, to my knowledge. Please note that I’m talking here about the naturally occurring forms vitamin K and K. Do NOT take synthetic vitamin K as it can harm you.
As shown by the complementary effects of vitamin D and K on bone, the fat-soluble vitamins can often act synergistic-ally. I recommend that you optimize your intake of vitamins A, D, and K.
The dietary sources for the fat-soluble vitamins tend to overlap, which is helpful. You can get your vitamin A from the same leafy green vegetables and liver that you’re going to eat for vitamin K and K intake, respectively.
Get your vitamin D from exposing your skin to sunshine, eating oily fish or taking D3 supplements. For more information on vitamin D see my previous post.
Alrighty then mate?
Of course, the good folks at team Athletic Greens were nice enough to put Vitamin K in the formula, but as always I want you to start with food. Athletic Greens is there for the supercharge component.
So get eat your delicious dark green vegetables, eggs and organ meats to ensure your vitamin K and A intake, and while you’re at it, get outside for some sunshine and vitamin D.
“100% Focus On Happiness”
That is my mantra, and it starts with phenomenal health.
Chris “the Kiwi”
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