Vitamin D, the “sunshine vitamin,” has garnered interest across many medical fields. For patients with hemophilia, boning up on bone health now may help prevent bone loss and fractures later.
Role of Vitamin D
The human skeleton appears to be solid. However, the body is constantly breaking down old bone material and building new. If net loss exceeds net gain, osteoporosis, or bone thinning, begins. Weak bones can increase the risk of fractures.
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Vitamin D helps the body use calcium. It can be obtained from the sun, certain foods, vitamins and supplements. In the skin, ultraviolet B (UVB) rays are converted to an inactive form of vitamin D. The liver and kidneys then change the vitamin D to its usable forms. Light-skinned people produce more vitamin D than dark-skinned people, who have more melatonin, a pigment that blocks the UVB rays. Salmon, tuna and sardines are good sources of vitamin D, as are foods fortified with it, such as milk, orange juice and cereals.
In a study published in 2010 in The Journal of Bone and Joint Surgery, of 723 orthopedic surgery patients at the Hospital for Special Surgery (HSS) in New York, 43% had insufficient vitamin D levels in their blood; of those, 40% had deficient levels. Interestingly, low vitamin D levels were more common in men than women, and in younger patients (18 to 50 years old) vs. older patients (51 to 70 years old). Further, blacks and Hispanics were 5.5 times more likely to have low levels of vitamin D than whites and Asians. Inadequate levels of vitamin D prior to surgery can mean poor healing, or bone and muscle weakness afterward.
“This study should serve as a wake-up call to orthopedists that vitamin D deficiency is widespread, not necessarily tied to age, sex or background, and screening for it should be part of routine pre-surgical care for adults,” said Joseph M. Lane, MD, a study co-author. He is chief of the metabolic bone disease service at HSS.
For people with hemophilia, bone health may be compromised by multiple factors, including repeated joint bleeds, HIV and hepatitis C. Some HIV drugs prevent bone mineralization, which leads to osteoporosis. Further, some components of HIV can stimulate cells that break down bone.
Chronic liver disease from long-term infection of hepatitis C also contributes to osteoporosis. Because the damaged liver cannot change vitamin D to a usable form, calcium is not absorbed properly. “A number of articles have documented the fact that many hemophilia patients have reduced bone density,” says James V. Luck Jr., MD, chief of orthopedics, Hemophilia Treatment Center, Los Angeles Orthopaedic Medical Center. (See “Learn More” section.) “This may be the result of many causes, such as limited activity, nutritional imbalances and even possibly some medications.”
RDA of Vitamin D
In November 2010, the Institute of Medicine, the health arm of the National Academy of Sciences, published a consensus report stating that most Americans are currently getting enough vitamin D and calcium. The Recommended Dietary Allowance (RDA) for people ages 1 to 70 is 600 international units (IU) per day. For people 71 and older, the amount is 800 IU daily. However, people with existing osteoporosis, HIV and/or hepatitis C may need more.
If you’re concerned about your bone health, ask your doctor about vitamin D and bone density tests.