By Benjamin V. Treadwell, Ph.D.

Vitamins have taken several significant hits lately for not delivering their purported health benefits. In fact, there are claims that, under specific conditions, some vitamins can actually have a negative effect on health. In contrast, experts have also recently become aware that the current recommended dietary amounts of some vitamins are far below what is needed for maximum health. Who is responsible for those recommendations and how will they change?

Initially, vitamin D was believed to help prevent the inadequate bone mineralization that progressed to the disease known as rickets in children and osteoporosis in adults. Consequently, the RDA for vitamin D was set to prevent bone-mineralization-associated diseases.

Research, however, has identified this vitamin’s contribution to numerous other biological functions, including a potential role in preventing breast and prostate cancer, tuberculosis, autoimmune diseases, and other disorders unrelated to bone mineralization. (For a review of new vitamin D findings, visit the following articles see Vitamin D - Recent Provocative Discoveries, Vitamin D - A Hormone with New Health Benefits, and Vitamin D — A Vitamin In Need of Revision.) Furthermore, there are more vitamin D receptors whose functions have yet to be discovered, in organs such as the brain.

In other words, the current recommended dose of 400 IU appears to be far short of what many require for maximum health, especially the elderly and those with pigmented skin and/or minimal exposure to sunlight. As a result, the government is scrambling to establish a new, significantly higher RDA. The maximum safe dosage may also be increased by a factor of at least 5 to 10 times the current recommended daily intake.

Another Story: Vitamin K
In 1943, Danish biochemist Carl Dam shared a Nobel Prize for his work on discovering a substance required for the clotting of blood: vitamin K. Taking its name from “koagulation,” Danish for coagulation, vitamin K functions as a cofactor for an enzyme (gamma glutamylcarboxylase) involved in modifying specific amino acid residues in several proteins to convert them from inactive to active blood-coagulating proteins.

People who lack sufficient amounts of vitamin K have a prolonged clotting time that can result in severe bleeding problems or hemorrhage. The recommended daily intake of vitamin K was initially estimated to be between 90 and 120 micrograms/day, the amount required for normal clotting time. It turns out that this amount is fairly easy to obtain from a diet rich in green, leafy vegetables (spinach, broccoli, lettuce). Bacteria residing in our intestines produce an even more potent form of vitamin K, vitamin K2, to help supplement what is supplied by diet.

These bone-specific proteins function in a way analogous to the steel reinforcement rods that give concrete its tensile strength. This is especially important in post-menopausal women and the aged, who have an increased rate of bone loss and increased incidence of osteoporosis and fractures.

As an even more effective method of increasing bone formation and strength, new data supports taking vitamin K, vitamin D and calcium in combination. The bottom line, to further our steel and concrete analogy: vitamin D and calcium help to promote the formation of "cement" in bone, while vitamin K may help promote the production of the bone-strengthening "reinforcing rods."

Blood Thinners and Bone Loss
Data from patients taking the blood thinner Coumadin® (aka warfarin) over long periods of time also seems to identify vitamin K as an important factor for bone formation. Coumadin, often used to treat an abnormally high tendency to form blood clots, effectively interferes with the normal process of recycling vitamin K from an inactive oxidized state to an active reduced state. The net result of this interference is that active vitamin K is less available as a cofactor to initiate blood clot formation.

Although Coumadin may help prevent stroke and other clot-related pathologies, it is also associated with a significantly higher incidence of osteoporosis (loss of bone density) than in age-matched people not taking the drug. Even more alarming, however, are recent results from animal studies showing that inhibiting vitamin K with Coumadin can promote the development of calcified plaques in blood vessels.

The implication is that atherosclerosis may, in part, be associated with low levels of vitamin K. In fact, the arterial plaque in the Coumadin-treated animals could be reduced or even eliminated by feeding the animals high doses of vitamin K2. Whether this applies to humans has yet to be determined.

What we do know is that people with atherosclerosis as well as osteoporosis have protein markers in their blood indicative of low levels of vitamin K. Furthermore, as we age, these same markers increase along with the incidence of osteoporosis and atherosclerosis. Consequently, should there be an age-associated increase in daily vitamin K intake?

Enough K Today
Except for Coumadin patients, there is no evidence that taking vitamin K in higher doses – even those far exceeding the RDA -- is dangerous to our health. However, unless a higher dose is recommended by a qualified health professional, the vitamin K from a healthy diet and multi-vitamin supplements should be sufficient for most people. Until more research is completed on higher doses for the prevention of certain diseases as described above, a nutritious diet with lots of green leafy vegetables may be the best method for obtaining a sufficient amount of this vitamin.

American and Japanese physicians, from a number of prestigious institutions specializing in critical care, pediatrics and geriatrics, have summarized recent work that demonstrates the broad range of biological activities associated with vitamin K.

The investigators point out the surprising evidence implicating vitamin K deficiency as potentially associated with a host of diseases including osteoporosis, atherosclerosis, osteoarthritis and liver cancer. They underscore the finding that many individuals who go on to develop these diseases appear to have normal vitamin K status as judged by normal hemostatic or blood-clotting activities.

The accumulated information from studies on vitamin K and its diverse activities suggests that this vitamin should be more intensely investigated. The current studies clearly indicate that some individuals, especially the elderly, may be deficient in this vitamin and could benefit from increased intake of vitamin K.

To read the abstract, click here.
"Pleiotropic actions of vitamin K: protector of bone health and beyond?"
Nutrition, Volume 22, Issue 7-8, Pages 845-852.

This Research Update column highlights articles related to recent scientific inquiry into the process of human aging. It is not intended to promote any specific ingredient, regimen, or use and should not be construed as evidence of the safety, effectiveness, or intended uses of the Juvenon product. The Juvenon label should be consulted for intended uses and appropriate directions for use of the product.

QUESTION: Why do you put calcium and biotin in the Juvenon product? — Ralph

ANSWER: Calcium is added as a stabilizer. Biotin, or vitamin B7, participates as a cofactor involved in maintaining a constant level of metabolites in the mitochondria. If these metabolites are not at optimal levels, the main Juvenon ingredients will not function optimally... they, too, are cofactors involved in energy production in the mitochondria. So biotin is an important link in maintaining a constant flow of metabolites for maximum energy efficiency in the mitochondria.

Send your questions to AskBen@juvenon.com.
For more questions and answers, go to juvenon.com/product/qa.htm.

Benjamin V. Treadwell, Ph.D., is a former Harvard Medical School associate professor and member of Juvenon's Scientific Advisory Board.