The Sun and Vitamin D.

You may already know that Vitamin D is important for bone health.  If you follow health news, then you’ve also heard a lot lately about the many other benefits that touch health concerns ranging from asthma to cancer.  But did you know that despite all of these benefits, most Americans are deficient in Vitamin D? 

Vitamin D 101:

Vitamin D helps the body absorb calcium from food, so we’ve long known its association with bone strength and osteoporosis.  But today we know a lot more about the benefits of Vitamin D, and they are vast.  It’s now associated with lower risk of heart disease, high blood pressure, diabetes, and cancer.  It’s also showing promise in preventing or curing Crohn’s disease, in improved memory function and potentially in decreasing the risk of heart attack and stroke.  For a full fact sheet from the NIH, click here.

We are a deficient nation

The Recommended Daily Allowance (RDA) for children and adults is currently 600 IUs of vitamin D per day, though I’ve heard talk of that recommendation increasing which I think would be great.  Nevertheless, let's assume that's the right number.  By that standard, 60-75% of Americans are Vitamin D deficient.  Recently, a study showed that for trauma patients with broken bones or fractures, that number reaches 77%.  

 

One of the leading hypotheses on the reason for our deficiencies is our obsession with sunscreen.  We have done a great job reducing skin cancer risk, but we’ve inadvertently “protected” ourselves from the essential rays of the sun that allow our own bodies to create vitamin D.  In fact, sun light is our primary source of the vitamin!  To learn more about how sunlight is used in your body to create vitamin D, click here.

So what do we do now??

Easy Tips to Protect Yourself:

1. Eat food that contains Vitamin D.

As with any vitamin, I think it’s best to get all you can from food as opposed to supplements.  For vitamin D, the best sources are fatty fish (think salmon, tuna), but mushrooms, beef liver, cheese, egg yolks and several others also contain small amounts.  See the table below for more foods that contain vitamin D.  If you've read my other posts, you know I would not vote for the dairy sources of food to get your vitamin.  Why not dress up your eggs with leafy greens for breakfast?  One of our favorites!

2. Take a high quality supplement.

You'll notice as you peruse the table below that it's VERY hard to get enough vitamin D from food alone unless of course cod liver oil is your weakness, in which case, drink on, brave soul!  If you also live in a place where you don’t get year round sun (man, that’d be nice), then you probably need to take a supplement.  Some multi-vitamins now have 1000 IUs of vitamin D, which is great.  Otherwise, you can pick up a high quality Vitamin D3 supplement from your local store.  Try to take it with food that contains fat (olive oil, eggs, nuts, etc) since it is a fat soluble vitamin and doing so will help you absorb more.  

3.  Get some sun!

The guideline is to get 15-20 minutes of direct sun exposure every day if you can to help ensure you reap all of the health benefits discussed above.  It's hard in places with very long winters to get that much direct sun exposure, so supplementing is especially important in winter months.  If you live in a place with year-round sun, then direct sunlight will give you all you need - no supplementing for you! But remember, after you get your 15-20, go inside and apply sunblock.  

4. Talk to your doctor.

Vitamin D levels can easily be tested in your blood.   Simply ask your doctor to run the test for you.  This is especially important if you’re older, or at a higher risk of bone fracture.  If you are deficient, your doctor will likely prescribe you a high dose (e.g. 50,000 IU) supplement to take weekly for a month and you’ll be back to good in no time!  Just remember to keep supplementing with normal doses (or food, sunlight) after that.

Table from the National Institutes of Health:  Selected Food Sources of Vitamin D
Food	IUs per serving*	Percent DV**
Cod liver oil, 1 tablespoon	1,360	340
Swordfish, cooked, 3 ounces	566	142
Salmon (sockeye), cooked, 3 ounces	447	112
Tuna fish, canned in water, drained, 3 ounces	154	39
Orange juice fortified with vitamin D, 1 cup (check product labels, as amount of added vitamin D varies)	137	34
Milk, nonfat, reduced fat, and whole, vitamin D-fortified, 1 cup	115-124	29-31
Yogurt, fortified with 20% of the DV for vitamin D, 6 ounces (more heavily fortified yogurts provide more of the DV)	80	20
Margarine, fortified, 1 tablespoon	60	15
Sardines, canned in oil, drained, 2 sardines	46	12
Liver, beef, cooked, 3 ounces	42	11
Egg, 1 large (vitamin D is found in yolk)	41	10
Ready-to-eat cereal, fortified with 10% of the DV for vitamin D, 0.75-1 cup (more heavily fortified cereals might provide more of the DV)	40	10
Cheese, Swiss, 1 ounce	6	2

* IUs = International Units.

** DV = Daily Value. DVs were developed by the U.S. Food and Drug Administration to help consumers compare the nutrient contents among products within the context of a total daily diet. The DV for vitamin D is currently set at 400 IU for adults and children age 4 and older. Food labels, however, are not required to list vitamin D content unless a food has been fortified with this nutrient. Foods providing 20% or more of the DV are considered to be high sources of a nutrient, but foods providing lower percentages of the DV also contribute to a healthful diet.

Source: http://ods.od.nih.gov/factsheets/vitamind/