of. Increasing Daily Intake of Vitamin K Essential for Bone and Heart Health Claire Alrich Biochemistry Program, Beloit College, Beloit, WI. ABSTRACT
Vitamin K is the cofactor for an enzyme that catalyzes the carboxylation of glutamic acid (an amino acid which is important in healthy blood clotting and bone mineralization). (5)My hypothesis is that taking greater than the current recommended daily value for Vitamin K could decrease risks for early onset of age related diseases like osteoporosis and heart disease. My research consists of reviewing current peer reviewed sources on recent investigations into Vitamin K and its connection to preventive bone and heart care. A significant amount of research is congruent with my hypothesis that increasing the recommended daily value from 120 micrograms a day for men and 90 micrograms a day for women, to 1000 micrograms a day could have important health benefits and could help specifically with the weakening of bone tissue and the hardening of the arteries through calcification. Further research needs to be done to fully establish the connections between Vitamin K intake and bone and heart health. Additional research should be done as to whether Vitamin K works as just a preventive health supplement or if it can actually work to cure the disease once it has already begun to develop in the body.
Vitamin K works by activating the protein osteocalcin. This protein strengthens bone mass, which means Vitamin K works to prevent the bone density loss common among the elderly that is the cause for many cases of debilitating bone breaks and fractures (see figure 2) (2). Osteocalcin also decalcifies soft tissues found in the arteries, removing the plaque that has built up there over the years. Restoring arterial flexibility decreases blood pressure and prevents heart attacks which result from blockages in the arteries. Vitamin K has also been hypothesized to remove plaque built up in the ear canals that is the cause for loss of hearing as we age (5). In nature it is mostly found in dark leafy greens like kale, cabbage and spinach, however, it is difficult to gain the most beneficial amount of Vitamin K from diet alone, as shown in table 1 (4). My hypothesis is that the current recommended daily value of Vitamin K needs to be increased to obtain the optimal amount, and that an increase in Vitamin K intake would have important health benefits and could help specifically with the hardening of the arteries of the heart and the weakening of bone tissue which contributes to the disease osteoporosis.
The information on this poster was compiled from peer-reviewed literature sources, local food markets, and online dietary supplement providers.
The current recommended daily value for Vitamin K is 90 micrograms a day for women and 120 micrograms a day for men. However, new studies are showing that to receive the maximum benefits the daily recommended value should be as high as 1,000 micrograms a day . Women who took 1000 micrograms a day of Vitamin K for two weeks showed increases in several of the biochemical markers of bone formation (2). A trial for a Vitamin K based supplement conducted on 325 postmenopausal women in Japan showed a significant decrease in fracture risks. The study showed a 60 % lower risk for vertebral fracture, a 77% lower risk for hip fracture and a 81% lower risk for non-vertebral fractures (5). However, another study showed that taking 500 micrograms a day of Vitamin K did not help increase bone density in older adults. This seems to indicate that an amount greater then 500 micrograms a day needs to be taken in order to see an affect on bone density. Researchers have also looked at the connection of Vitamin K and the supplements of Vitamin D and calcium. It showed that when they are taken together there is a increase in bone density, but the study was not conclusive as to the optimal amount of each supplement. This also throws uncertainty onto which vitamin has the greatest affect on bone health since all three have been shown to have some connection to the prevention of the loss of bone density(4). Studies are also showing that Vitamin K can clear out plaque from the arteries of the heart, hugely cutting down risks of heart attack. One study of post-menopausal women showed that those with high amounts of aortic calcification generally had lower dietary intake of Vitamin K. This indicates that insufficient dietary Vitamin K can contribute to a higher risk for heart attack due to calcification of the arteries which ingesting high amounts of Vitamin K daily helps to prevent and reverse (5).
Figure 1: Chemical structure of Vitamin K
Table 1 shows that it is possible to get the ideal amount of 1,000 micrograms a day of Vitamin K from diet alone. A 10 oz serving of frozen Spinach supplies 1189.5 mcg of Vitamin K. Dark leafy greens are the foods that have the highest concentration of Vitamin K. It is fairy easy to get the current recommended amount of Vitamin K (120 mcg per day for men and 90 mcg for women) by eating a daily serving of almost any of the dark greens represented in Table 1. However, it is more difficult to obtain what researchers are defining as the new optimum amount (1000 mcg per day) from diet alone (4). It is possible to get this amount from spinach (which has 1189.5mcg of Vitamin K), but taking a supplement is a way to precisely monitor and regulate your intake. It appears that getting a high amount of Vitamin K (close to 1,000 micrograms a day) is a ideal for older adults, especially postmenopausal women, because it decreases calcification of arteries which leads to heart disease, and it helps reduce bone loss which reduces risk of developing bone related disease like osteoporosis. Currently there is no upper limit for Vitamin K because no adverse side affects have yet been reported about taking large amounts of it. This is most likely because the body does not produce Vitamin K independently, but it is a substance necessary for the body to function (5).
My research supports my hypothesis that the current recommended daily value of Vitamin K should be increased. Current research is showing that Vitamin K deficiency is a major contributing factor to the early onset of age relate diseases, like heart disease and osteoporosis. Research being done with osteoporosis shows that taking a high amount of Vitamin K can help prevent the onset of the disease, but it can also help reverse some of the symptoms of the disease when they have already begun to advance. Vitamin K can reduce the rick of coronary heart disease by preventing the hardening of arteries that occurs over time. However, to receive the benefits Vitamin K it needs to be taken in amounts as high as 1000 mcg a day. This means the recommended daily value of 90 mcg per day for women and 120 mcg per day for men is likely to be increased. Further research needs to be done to determine the precise levels of Vitamin K that contribute to increased bone and heart health, but research seems to indicate that it should be close to 1000 mcg per day. Eating a healthy diet full of dark, leafy green vegetables is important to maintain a healthy amount of Vitamin K in the body, but those especially at risk for osteoporosis and heart disease might want to take a supplement in order to assure they receive the optimal daily amount.
Table 1: List of Foods High in Vitamin K (4)
Figure 2: Comparison of a normal bone image and the bones of someone with osteoporosis - Vitamin K helps to rebuild lost tissue and prevent further damage, it is especially effective when combined with vitamin D