Why as a Minnesotan, would I need to be concerned about Vitamin D?
Vitamin D enhances our absorption of calcium, thus helping to build and maintain strong bones. Without adequate Vitamin D, bones become brittle, thin and soft. The weakening of bones increases the risk of fractures and bones diseases such as rickets, osteomalacia and osteoporosis.
Vitamin D is also known as the “sunshine vitamin”. For a good reason, with enough sun exposure, our bodies will make all the Vitamin D we need. However if you are not exposed to enough sunlight you may not get enough Vitamin D. The same is true if you have a hard time metabolizing Vitamin D or have reduced liver or kidney function. The amount of Vitamin D produced in the body from sun exposure can vary greatly depending on one’s age, location of latitude, time of day, smog and the use of sunscreen. As we all age, our bodies do not work as well as when younger. For example, a 70-year-old makes only 25% of the Vitamin D that a 20-year-old person makes.
Your location is very important in determining the amount of Vitamin D produced from the sun. In most of the U.S. you cannot make Vitamin D from sunlight for 4 months of the year. If you live in the Northern US or Canada it may be difficult in as many as 7 months. Moreover, using sunscreen reduces the amount of Vitamin D produced through sun exposure. A sunscreen with an SPF of 8 or better will block 90% of the rays that you need to produce Vitamin D.
You can get Vitamin D from foods. However, it is difficult to acquire optimal levels from your diet alone, because Vitamin D occurs naturally in very few foods.
Fatty fish (salmon) and certain oils naturally contain some Vitamin D. Breakfast cereals and milk are fortified with Vitamin D. A quart of milk will have about 400IU of Vitamin D.
There is not complete agreement on the optimal daily dose of Vitamin D. Current recommendation is 600-800IU per day. Since absorption from supplements is poor. The recommended supplement dose is 4000 IU.
It is very rare that you would get too much Vitamin D. If you did, it would cause a high calcium level in your blood, known as hypercalcemis.
Hope this informs you about Vitamin D. The next time you visit with your primary care provider, ask them to test for your Vitamin D level.
Blog Written By: Denise Gilbertson, Nutritional Service Manager