Vitamin D - The Sunshine Vitamin

By: Dr. Sarah Vincent, ND

Vitamin D is essential to your body’s functioning and overall health. Vitamin D is a fat soluble vitamin so it requires fat in order for it to be efficiently absorbed by your body.  Vitamin D helps the body absorb calcium from food and supplements which helps build bone density. 

What does vitamin D do? 

It helps your body absorb calcium to help build strong bones and teeth, it strengthens your immune system (and may inhibit the development of autoimmunity), it strengthens your muscles, helps with cell differentiation (prevents abnormal cell growth) and helps to carry messages in your brain and may help with mood and cognitive function!

Which foods have significant amounts of vitamin D?

Have some fish for dinner! Fish such as snapper, whitefish, mackerel, salmon, trout, halibut, sardines, herring, and tuna are highest in vitamin D. Fortified beverages such as cow, soy, almond and coconut milks also have significant amounts. Mushrooms are not typically a good source of vitamin D, but some companies are now growing their mushrooms under UV light to promote vitamin D production. Dole’s Portobello mushrooms are grown this way and will give you roughly 400IU of vitamin D per cup of diced mushrooms.

Get outside!

If you spend a lot of time outside in the summer, you’re likely getting a healthy dose. Solar UVB (ultraviolet-B rays: wave length 290-315nm), stimulate the production of vitamin D in your epidermis. Most people can get their full requirements of vitamin D, just from being out in the sun two to three times a week for 30 minutes! 

So how do you get the vitamin D that you need? According to Dr. Holick, as little as 5-10 minutes in the sun, three times a week, at peak times (between 11am and 2pm), during the months of March to late October, should be enough for the average light-skinned individual to get their required dose and provide storage for vitamin D shortage during the winter, with minimal risk of skin damage. (3) Note that light exposure through a window doesn't work.

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What about tanning beds?

I personally am not opposed to tanning beds, but I am also not encouraging overuse. The key in exposing yourself to any amount of UV radiation, whether through indoor tanning or outdoors, is to ensure that you do not overexpose yourself. Moderate and frequent exposure is healthy, but intense, overexposure can be damaging and increase your risk of developing skin cancer. The key here is moderation.

The UV light the tanning bed bulbs emit is important, but do keep in mind that both UVA and UVB rays are damaging to the skin with overexposure.  UVB rays are what your body uses to make vitamin D and they are not as strong/intense as UVA rays. UVA rays penetrate deeper layers of the skin and are what causes your skin to tan, while UVB rays are not as strong and penetrate only the tops layers of the skin and are the ones responsible for sunburns. In order for your body to make vitamin D, you do not need to tan. Often, 10-15 minutes maximum in the sun, without sunscreen or sunblock, is enough for your body to make the vitamin D that it needs.

What about supplementation?

Supplementation is a good idea, if you don’t get out in the sun often, or if you know you have a deficiency.  There are also certain illnesses that benefit from supplementation with vitamin D. Below are the recommendations for daily intake. 
 
Age Group      -            Recommended daily allowance (IU)
0-12 months    -    400-1000 IU
1 year – 8 years    -    400-1500 IU
9 years – 70 years    -    600-4000 IU
70 years and up    -    800-4000 IU
Pregnancy & Lactation     -    600-4000 IU

*The DRIs for vitamin D have been set assuming minimal sun exposure for all, which means that additional recommendations are not required for sub-populations such as those at high northern latitudes, those with darker skin pigmentation, or those with heavy clothing that inhibits sun exposure. (4)

  Brands that I personally like, are AOR’s Liquid D3 drops, and Ddrops®. Both brands use coconut oil as the carrier oil and are free of all major allergens. Be sure to read the label on any supplement you are thinking of taking, to make sure it’s a clean product, free of fillers, binders, colors, artificial flavorings and all major allergens! Look for D3 (cholecalciferol), which is the active form of vitamin D.

Still have questions?
Make an appointment with me and we can talk about it! 
 

REFERENCES
(1)Plotnikoff GA, Quigley JM. Prevalence of severe hypovitaminosis D in patients with persistent, nonspecific musculoskeletal pain. Mayo Clin Proc. 2003;78(12):1463-1470.  (PubMed)
(2)Bringhurst FR, Demay MB, Kronenberg HM. Mineral Metabolism. In: Larson PR, Kronenberg HM, Melmed S, Polonsky KS, eds. Larsen: Williams Textbook of Endocrinology: Elsevier; 2003:1317-1320.
(3)Holick MF. Vitamin D: the underappreciated D-lightful hormone that is important for skeletal and cellular health. Curr Opin Endocrinol Diabetes.
(4)http://www.hc-sc.gc.ca/fn-an/nutrition/vitamin/vita-d-eng.php#a10, Mar.3, 2014.