December 9, 2014 | by Cynthia Smyth MD

It’s that time of year again when the days are getting shorter and darker. For many people, the sun is not yet up when they leave for work, and it is dark outside when they leave work to head home. Most people work inside all day, and so are not exposed to any sunlight during the winter months. The sun is an important source of vitamin D, which has been in the news quite a bit lately for all its beneficial effects on health.

Vitamin D is very important for bone health, and having chronically low levels of vitamin D can put you at risk for weak bones, such as osteoporosis. Patients with osteoporosis are at a high risk for fracture. Women have a higher risk for osteoporosis after they go through menopause, as they no longer have estrogen strengthening their bones. Patients on steroids are also at increased risk for osteoporosis, as those medications break down bones.

The most common fractures seen in patients with osteoporosis are fractures of the spine, hip, and wrist. Spinal fractures can often occur spontaneously in patients with osteoporosis, without even having had a fall. They can be quite painful and leave patients hunched over, appearing to lose inches of height. Hip fractures require surgery and months of rehab to recover from. They put people at risk for very serious complications such as pneumonia and blood clots, which can both be fatal.

Maintaining normal vitamin D levels, as well as regular weight-bearing exercise, can help prevent osteoporosis. Here in Seattle where we get far less sunshine than in many parts of the country, I recommend that patients take 2000 IU’s of vitamin D 3 daily, which can easily be found over-the-counter. Foods that are good sources of vitamin D include milk, yogurt, cheese, and salmon. The large Women's Health Initiative study found that women who had low levels of vitamin D had a higher incidence of colon cancer compared to patients with normal vitamin D levels. Ongoing research is looking into the relationship of vitamin D in helping to prevent against breast cancer, prostate cancer, diabetes, heart disease, depression, and multiple sclerosis.

During the summer when the sun is out quite a bit, you can get your daily dose of vitamin D just by having your face exposed to sunlight for 15 minutes. It only takes a few weeks of winter however, for vitamin D levels to be depleted once the sun is no longer out on a regular basis. I recommend that all of my patients get their vitamin D level checked, and if low (which I find it usually is in Seattle), take a vitamin D supplement. Nursing home patients, who often never get outside to see the sun, may need to take a prescription-strength vitamin D medication of 50,000 IU’s once a week to maintain normal levels. I do not recommend using tanning beds during the winter, as these have been shown to increase your risk of skin cancer, and provide no vitamin D whatsoever.


Dr. Cynthia Smyth is an internal medicine doctor who specializes in preventive medicine as well as managing chronic medical conditions such as diabetes and high blood pressure. She is located at The Polyclinic Downtown at 509 Olive Way, Seattle, WA 98101



Written By: Cynthia Smyth MD