Why Vitamin D is Key

by Kelsey Denney

Vitamin D has long been linked to bone health, so why are we suddenly finding vitamin D smack dab in the the center of the news-media spotlight? Well, it has a lot to due with the release of new research revealing alarmingly widespread vitamin D deficiencies, and the fact that there is a lot of compelling research linking prolonged insufficient levels of vitamin D to a multitude of diseases, chronic conditions, and poor immune functioning. So after recently receiving a letter from my doctor following a routine check-up informing me that I had a significant vitamin D deficiency, I decided it was time I better start paying attention to all the attention being paid to vitamin D, and figure out how I, as vegetarian living in the perpetually overcast pacific northwest, can get enough of it.


So what is vitamin D and what does it do?

Although we refer to vitamin D as a "vitamin," in truth, it is actually a hormone, and an important one that contributes to a number of important functions within our bodies [1]. Historically, vitamin D has been noted for its role in bone health. Through helping our bodies absorb calcium, and helping to maintain adequate blood concentrations of calcium and phosphate, vitamin D helps our bones stay strong and dense [1]. Research has also shown that vitamin D has important interactions with several types of tissue throughout our bodies including cells of the "immune system, brain and nervous system, pancreas, skin, muscles and cartilage, and reproductive organs" [1]. These interactions are partly why vitamin D deficiency is so important to our overall health and disease prevention.


How do we get vitamin D?
We can get vitamin D in two different ways, our bodies can produce vitamin D after exposure to adequate amounts of sunlight, and we can consume foods or supplements that contain vitamin D. In the pacific northwest region, and for that matter in most locations above 40 degrees north latitude and below 40 degrees south latitude, inadequate levels of sunlight are available to stimulate the production of vitamin D throughout the dreary winter months [1]. Thus, obtaining vitamin D from food sources becomes vitally important for people living in these areas, and for anyone who is often confined inside and doesn't get regular exposure to direct sunlight.

The food sources that include the most concentrated sources of vitamin D are several types of fish including mackerel, tuna, salmon, sardines, and fish liver oil [2]. However, there are several vegetarian foods that also contain smaller amounts of vitamin D including eggs, and swiss cheese [3]. There are also a host of foods fortified with vitamin D that are vegetarian including cow's milk, soymilk, most breakfast cereals, orange juice, and certain brands of yogurt and margarine [2]. For vegans, and for vegetarians that don't drink a lot of cow's milk, a vitamin D supplement will be needed to maintain adequate levels of vitamin D [1]. Most vitamin D supplements come in the form of gelatin capsules and are not vegan. However, vegan friendly vitamin D supplements are available and can be found at certain pharmacies, health food stores, and ordered online. Additionally, research into fortifying mushrooms with vitamin D through concentrated sun exposure is currently being conducted, and soon fortified mushrooms may be available as another vegetarian/vegan vitamin D option [3].

What are normal vitamin D levels and how can you get your vitamin D levels tested?
To get your vitamin D level tested you will need to go to the doctor and get a blood test. In some areas, like the Pacific Northwest where I live, this is becoming a fairly routine part of an annual checkup, but you may need to request the test and discuss with your doctor whether or not you are at risk for vitamin D deficiency. After the test, your doctor will determine whether or not you have an adequate vitamin D level, which will depend on several factors including overall health history, age, and gender, but in general the Office of Dietary Supplements states that levels of vitamin D consistently between 35-75 nanograms per milliliter (ng/mL) are "desirable for overall health and disease prevention" [2].

Should you be taking a vitamin D supplement?
You and your doctor together should answer that question, and testing your current vitamin D levels will be an important part of that equation. It is important to remember that recommended intake of vitamin D levels varies depending on many factors including age, location,exposure to direct sunlight, skin color, gender, health history, and what source you are consulting. The Office of Dietary Supplements current daily recommended vitamin D intakes for those not exposed to adequate sunlight are: 200 IU for people from birth to 50 years old, 400 IU for people 51 to 70, and 600 IU for those over 71 [2].
Also, all vegans need to supplementing their vitamin D intake, and vegetarians should strongly consider this as well especially if they live above the 40th north or below the 40th south parallels [1].


Again, it is important to remember to consult your doctor before beginning a vitamin D or any vitamin supplement regimen. They will determine whether supplements are needed and what levels are most appropriate for you. Vitamin D supplements can also interact with a variety of medications so it is super important to check with your doctor before you start taking a supplement. If you have a history of vitamin D deficiency, your doctor may recommend a higher daily supplement of vitamin D for you. For example, after taking a high prescription dose of vitamin D to initially restore my vitamin D levels to a healthy range, my doctor has recommended that I take a 1000 IU vitamin D supplement daily for the rest of my life. You doctor may recommend something similar, or something completely different depending on your health history, and other medications you take. And in case you missed it the first 3 times I said it, check with your doctor before you start taking vitamin D or any vitamin supplements.

What are some of the diseases and chronic conditions that may be linking to prolonged vitamin D deficiency?
-rickets (in children, causes bone and skeletal deformities) [1,2]
-osteoporosis and osteomalacia [1,2]
-bone and muscle weakness and pain [1]
-certain cancers including colon, prostate, and breast cancer [2]
-multiple sclerosis [2]
-high blood pressure [2]
-type I and type II diabetes [2]



Sources:

1. Whitney and Rolfes. "Understanding Nutrition." Thompson Wadsworth. 2009.
2. Office of Dietary Supplements. National Institutes of Health. 5 Aug 2009 <http://ods.od.nih.gov>
3. Mangels, Reed. "FAQs about Vitamin D." April-June 2009. Vegetarian Journal. 5 Aug 2009 <http://findarticles.com/p/articles/mi_m0FDE/is_2/ai_n31637187/?tag=content;col1>


Article by Kelsey Denney, August 2009

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