D, the sunshine vitamin – Monadnock Ledger Transcript
With the equinox last week and the leaves starting to change, it’s a good time to talk about vitamin D, the sunshine vitamin. As the days get shorter and the nights longer, it becomes more difficult for us northerners to get all the sunshine we need to produce adequate amounts of this important vitamin.
One of the roles of vitamin D is to influence proper functioning of the immune system. Deficiency can put you at risk for infections. Since the winter season is on its way, with the cold and flu season right around the corner, this is a great time to learn more about vitamin D, what it can do for us and the best ways to get it.
Why do you need it?
Vitamin D is considered the sunshine vitamin because sunlight on our skin produces a substance which is a precursor of vitamin D. Vitamin D is actually more like a hormone than a vitamin. It has far reaching effects on the human body. In addition to supporting your immune system, it plays a major role in the development of good bone health and the prevention of chronic diseases. Its preventative effect is largely due to the fact that it is a powerful anti-inflammatory. Research indicate it may play an important role in the prevention of diabetes, certain cancers, multiple sclerosis and other auto-immune disorders; depression, heart disease, high blood pressure, and stroke.
How can you get more?
Very few foods in nature contain vitamin D. Fatty fish (such as salmon, tuna and mackerel) and fish liver oils are among the best sources. Small amounts of vitamin D are found in beef liver, cheese, and egg yolks. Some mushrooms provide vitamin D but it is in the less absorbable D2 form.
Fortified foods provide most of the vitamin D in the American diet. For example, almost all of the U.S. milk supply is voluntarily fortified with 100 IU/cup. Other dairy products made from milk, such as cheese and ice cream, are generally not fortified. Ready-to-eat breakfast cereals often contain added vitamin D, as do some brands of orange juice, yogurt, and other food products.
If you aren’t eating these foods regularly, it’s challenging to get adequate amounts of D.
Is sunlight a good source of vitamin D?
Some scientist say sunlight is the best source of vitamin D. Unlike dietary or supplementary vitamin D, when you get your ‘D’ from sunshine your body takes what it needs, and de-metabolizes any extra. Because too much ‘D’ from dietary supplements may cause the body to over-process calcium, it is unclear how much supplementary vitamin D is safe. On the other hand, sunlight-induced vitamin D doesn’t have that problem.
Sun exposure for 10 to 15 minutes per day to the arms and legs should be adequate but bear in mind it varies depending on fairness or darkness of skin. And most importantly to those of us who live in the Monadnock region, sunshine is too weak at certain times of year, like winter, to make any vitamin D at all. Not to mention, who wants to bare their arms and legs in frigid temperatures.
What about supplements?
If you are challenged with getting enough time in the sun which many of us are because we work during the day, you might want to consider supplementation. This is especially true since some researchers say three-quarters of adults and teens in the U.S. are deficient.
The NIH recommends daily intakes of 600 to 800 IUs per day. But this doesn’t take into consideration if you are deficient in the first place. Some scientists, nutritionists and doctors are much more aggressive recommending 5000 IUs and more because of the significant effects of vitamin D on disease prevention.
My best advice is to get your vitamin D level checked the next time you visit your doctor. It’s best to know your numbers so you can make better choices. In the meantime, daily supplementation of 1,000 IUs of vitamin D3, especially considering we live in southern New Hampshire, can be a smart strategy.
Ruth Clark is a registered dietitian nutritionist with a master’s in public health and over 35 years of experience. She lives in Sharon and has offices in Peterborough and Amherst. After losing both her parents to heart disease at a very young age, nutrition became her purpose in life and she is passionate about helping mid-life individuals prevent illness.