Vitamin D has received a lot of attention lately. We know Vitamin D is important for health by promoting the absorption of calcium from the intestines. If Vitamin D levels are too low, or deficient, adequate calcium cannot be absorbed. Vitamin D is necessary for bone growth during childhood and adolescence, bone healing for fractures, and together with calcium, Vitamin D helps protect older adults from weakening of the bones, or osteoporosis.
Vitamin D has other important roles in the body. This vitamin is important for regulating the growth of cells, preserving immune function, and reducing inflammation. Vitamin D has also been shown to help stabilize various genes and our DNA. Recent studies support Vitamin D for breast cancer prevention. Vitamin D acts as a hormone to help stabilize cell growth in the breast, and may help reduce the risk of breast cancer. We know there is an increased incidence of Vitamin D deficiency (or low Vitamin D levels), in women who are diagnosed with breast cancer. Maintaining normal Vitamin D levels after a diagnosis of breast cancer is important, and may help stabilize breast tissue, and reduce the risk of recurrence. We also know the treatment of breast cancer has been associated with Vitamin D deficiency, particularly in women who need anti-estrogen medication. Studies have shown that many of the musculo-skeletal symptoms in women, particularly in women taking anti-estrogen medication, may be relieved by normalizing the level of Vitamin D. This is exciting and new information, and helps us in our ability to care for patients, and maintain a good quality of life during breast cancer treatment.
Most people receive some, though not all, of their Vitamin D needs through exposure to sunlight. Vitamin D is also produced in our body when skin is exposed to ultra-violet light. However, the amount of sunlight exposure to produce adequate Vitamin D may be excessive; we are cautioned to avoid excessive sun exposure to reduce the risk of skin cancer. Most people use or should use sun screens, which further reduce the effect of ultraviolet light on Vitamin D production. Vitamin D is a fat-soluble vitamin, and is present naturally in very few foods. Some food, such as milk and dairy products, may be fortified with Vitamin D, and fortified foods provide most of the Vitamin D in the American Diet. Common food sources of Vitamin D include;
• Salmon, or mackerel — 400 IU per serving
• Fortified milk — 100 IU per serving
• Fortified orange juice — 100 IU per serving
Vitamin D is also available as a dietary supplement, and most Americans require some supplemental Vitamin D in addition to their diet and exposure to sunlight. Low levels of Vitamin D, or Vitamin D deficiency is more widespread than realized. It is estimated a many as 20-30% of Americans may be deficient, and 50 percent of Americans have insufficient levels. Certain groups of individuals are at increased risk for Vitamin D deficiency, and include
• Dark skinned individuals
• Individuals who receive little sun exposure
Generally, Americans need 3000-4000 IU Vitamin D daily to maintain normal levels. Since food sources do not provide sufficient Vitamin D, supplementation with Vitamin D may be necessary. However because Vitamin D is fat-soluble, and is stored in our fat cells, it is important not to take excessive doses of Vitamin D, which can be harmful. Women, particularly post-menopausal women should have a Vitamin D level checked with a simple blood test. If it is normal or low, your physician can recommend the appropriate amount of Vitamin D supplement for you.
In summary, Vitamin D is important for the health of all Americans. Maintaining normal Vitamin D levels can help reduce the risk of osteoporosis and is important for reducing breast cancer risk, and alleviating some of the symptoms associated with breast cancer treatment. Please consult your doctor before starting a Vitamin D supplement.
ABOUT DR. VIRGINIA HERRMANN
Dr. Herrmann is the Medical Director of the Breast Health Center at Hilton Head Hospital, and has more than 25 years experience as an oncology surgeon dedicated to caring for patients with breast disease. She was fellowship trained at Harvard University, and is Professor of Surgery at the Medical University of South Carolina and a member of the MUSC Hollings Cancer Center Comprehensive Breast Care Team. Dr. Herrmann is also a member of the American College of Surgeons Oncology Group and the Society of Surgical Oncology. She sees patients in Hilton Head, Bluffton, and Charleston