Vitamin D is very hormone-like in its actions within your body and contributes to a wide variety of functions, including enhancing immune response, building strong bones and maintaining healthy blood vessels. Along with vitamin K, vitamin D is also required for normal blood clotting when your blood vessels are breached, although it can be used to discourage inappropriate clotting within people who are sick and bedridden.
Vitamin D
Vitamin D, specifically cholecalciferol, is produced within your skin in response to certain frequencies of sunshine. Not enough vitamin D can lead to osteomalacia, or soft bones, osteoporosis, poor immune response, depressed mood and hardened arteries, as cited in "Vitamins: Fundamental Aspects in Nutrition and Health." Serum concentrations of calcidiol are measured to determine if you have enough vitamin D within your body, and levels below 37.5 nanomoles per liter are considered deficient. According to "Nutrition and Public Health," up to 75 percent of Americans are deficient in vitamin D, which is mainly due to lack of appropriate sun exposure. Many Americans avoid the sun due to fear of skin cancer and skin deterioration, but others live in northern climates that don't receive enough UV radiation.
Vitamin D Recommendations
The National Institutes of Health recommends 600 IU of vitamin D per day for adults up to the age of 70 and 800 IU for adults older than 70. These recommendations are merely meant to avoid obvious deficiency symptoms, so some health practitioners recommend more per day, between 1,000 and 5,000 IU, in efforts to enhance health, especially among the elderly and bedridden who spend less time in the sun.
Blood Clots
The blood clotting process is crucial to prevent your blood vessels from losing excessive blood and to help your body heal wounds. Vitamin K is the most important nutrient for blood clotting because it stimulates blood platelet cells to aggregate, or stick together, at injury sites. Vitamin D also contributes to normal blood clotting and keeps vessels flexible. However, blood clots can form abnormally in response to severe lack of movement and blood flow, which happens while bed-ridden due to sickness or treatment, especially chemotherapy. Blood clots can become life threatening if they completely block a vessel, especially one that is close to your heart or within your brain. An Oregon Health and Science University study published in a 2006 edition of the "British Journal of Haematology" found that high doses of vitamin D were very efficient in decreasing venous and arterial blood clots in patients being treated for advanced prostate cancer. Further, vitamin D from moderate sun exposure has proven to reduce the incidence of deep vein thrombosis, which is a type of blood clot that forms in people who are extremely inactive, bed-ridden in hospitals or women who smoke excessively and take birth control pills, as cited in "Human Biochemistry and Disease."
Sources of Vitamin D
The best source of vitamin D is sunshine, especially during summer months when UV radiation is higher. Wearing sunscreen prevents vitamin D production within your skin when you are outside. Vitamin D is not common in foods, but good sources include milk, fish and fortified margarines, cereals and juices, as cited in the "American Dietetic Association Complete Food and Nutrition Guide."
References
- "Vitamins: Fundamental Aspects in Nutrition and Health"; G. Combs; 2008
- "Nutrition and Public Health"; Sari Edelstein; 2006
- National Institutes of Health: Office of Dietary Supplements: Vitamin D Fact Sheet
- Oregon Health and Science University: OHSU Cancer Institute Researchers Find Activated Form Of Vitamin D May Reduce Blood Clots In Cancer Patients
- "Human Biochemistry and Disease"; Gerald Litwack; 2008
- "American Dietetic Association Complete Food and Nutrition Guide"; American Dietetic Association; 2006
