December 21st marks the winter solstice — the shortest day of the year — when people in the Northern Hemisphere receive the least amount of sunlight. With sunshine in short supply for the next few months, it’s a good time to focus on getting more vitamin D, also known as “the sunshine vitamin.”
Not long ago vitamin D was considered important only for bone health, but now we know that it’s a complex nutrient that may play a role in preventing autoimmune diseases, improving mental health, protecting our cardiovascular system, and fighting cancer. Some research shows that vitamin D may even help with weight management.
Unlike other vitamins, our bodies have the ability to make our entire requirement of vitamin D from sunlight, but reduced sun exposure in winter can result in inadequate levels. A recent University of California-Irvine and Mayo Clinic study found that serum vitamin D is highest in August and lowest in February. From November through March, the lack of UVB rays in the Northern Hemisphere means we can’t produce vitamin D from sun exposure to our skin.
How much vitamin D do you need? The official daily recommendation for vitamin D intake is 600 IU, increasing to 800 IU after age 71. However, some research indicates a benefit at levels as high as 2,000 IU.
So what should you eat to boost your food intake of vitamin D? Very few foods naturally contain vitamin D, and those that do have relatively small amounts. A notable exception is fatty fish, particularly wild Alaskan salmon. In fact one variety, Alaskan sockeye (red), offers a whopping 930 IU per 3.5 oz serving. For a hearty meal that’s sure to please your family, try Salmon with Asian Glaze.
Other food sources include fortified spreads (100-200 IU per Tbsp), fortified eggs (120 IU per 1 large egg), fortified soymilk and orange juice (check labels, but generally 100-130 IU per cup) and mushrooms (amounts vary depending on variety).
Taking a vitamin supplement during the winter might also be a good option if you are living in northern latitudes. Before starting a supplement, check with your doctor to see if you are vitamin D deficient.