Snow days, ski trips, ice skating and hot chocolate with marshmallows aside, there is one thing about winter that I don’t love … being pale! This isn’t because I look and feel better with a little color, but rather there is a lack of moderate, natural sun exposure that normally keeps my vitamin D levels in check. In the winter, it is imperative that we make up for the lack of vitamin D our skin produces via the sun through our own diet. A well rounded, healthful diet is one that should fulfill our daily requirements for vitamins and minerals. However, during the winter in colder regions, it is difficult to fulfill our requirement for vitamin D. This may seem alarming, but the majority of American’s aren’t receiving adequate amounts of vitamin D, actually 40% of the US’s population is Vitamin D deficient!
Vitamin D is not truly a vitamin but actually a hormone that is fat soluble and is integral for bone health. Since it is fat soluble, it can be stored in the body for later use. Its function may help prevent bone disease, breast and colon cancer, cardiovascular disease, multiple sclerosis, rheumatoid and osteoarthritis, osteoporosis and help prevent pre-eclampsia during pregnancy. There are also studies showing a possible correlation with lack of vitamin D and type I and type II diabetes, hypertension, gastrointestinal health and fertility. The active form of Vitamin D directly or indirectly controls over 200 genes in your body (talk about a hard worker!).
Moderate sun exposure is one of the best ways to get vitamin D because the skin has the capacity to synthesize it. 15-20 minutes of moderate sun exposure in the summer months (or vacationing to warmer climates during the winter) is equivalent to taking up to 20,000 International Units (IU) of vitamin D. Unfortunately, when the winter months hit, sun exposure rapidly declines and we have to make up for our lack of vitamin D. The best way to do this is through your diet, although if you are having extreme difficulty vitamin supplementation is also adequate. The daily recommended intake for vitamin D is 600 IU with the upper limit being 2,000 IU per day; and in the absence of sun exposure, 1,000 IU daily of vitamin D may be necessary. Nutritionally speaking, when you begin to drop below the required amounts of vitamin D your body will not absorb as much calcium either, because vitamin D increases the absorption of calcium and phosphorus which are vital for metabolic functions, bone health and neuromuscular functions. So it is important to keep up your vitamin D levels to maintain calcium and phosphorus levels in your body.
When people think of sources of vitamin D, most shop in the dairy aisle of their supermarket, but there are actually other non-dairy food sources that have higher amounts of vitamin D. Nowadays, many products such as cereals and juices are fortified with vitamin D so you can find it there as well. If you are interested in maximizing your diet with vitamin D here are some natural and fortified foods that can help you achieve adequate vitamin D levels, even when the sun is shining!
- Wild Salmon (3.5 oz) = 650 IU
- Tuna, canned (3.5 oz) = 230 IU
- Sundried Shitake Mushrooms (8) = 500 IU
- Egg (1 whole) = 20 IU
- Fortified Sources:
o Milk/Orange Juice/Yogurt (8 oz) = 100 IU
o Cereal (3/4 – 1 cup) = 40 IU