The importance of vitamin K for health
It has long been known that vitamin K, which is involved as a coenzyme in the production of coagulation factors, is essential to the regulation of blood coagulation. But vitamin K also fulfils an important role in the activation of certain enzymes which, together with vitamin D, regulate metabolism and can combat the harde- ning of soft tissues such as blood vessels and help slow bone demineralization. In recent years interest in this vitamin has grown considerably following the discovery of other poten- tially health-promoting properties. Attention centers on re- search into the function of vitamin-K-dependent enzymes (Gla proteins), which are found in bones and teeth as well as in blood vessel linings, the brain and other soft tissues, where they appear to regulate cell division and cell differentiation, among other things. Studies indicate that a sufficient intake of vitamin K could help prevent the occurrence of atheroscle- rosis, osteoporosis, insulin resistance and inflammation of the joints, and above all could protect against the age-related loss of cognitive abilities.
The importance of beta-carotene as vitamin A source
Vitamin A can be obtained from animal-derived foods as preformed vitamin A, or from vegetables and fruits as provitamin A carotenoids, mainly beta-carotene. In the Western diet, about 20 to 34% of the habitual intake of vitamin A originates from provitamin A carotenoids, while for the majority of individuals in developing countries over 70% of the vitamin A intake stem from provitamin A carotenoids in the diet. The food matrices of vegetables and fruits in which beta-carotene is incorporated have been found to exert a major influence on measured vitamin A equivalency of beta-carotene, defined as the amount of ingested beta-carotene in mg that is absorbed and converted into 1mg retinol (vitamin A) in the human body.
A new study from Iran suggests that low blood concentrations of vitamin D may increase the risk of developing a blood clot in one or more deep veins.
A new US study reports that high blood concentrations of antioxidant carotenoids and vitamin E in young adulthood may reduce the risk of developing cardiovascular disease in middle age.