The human body is so cool. We can use the sun to produce a valuable, vital-for-life vitamin inside of us. Ultraviolet (UV) light, to be exact, penetrates our skin and converts cholesterol into a inactive version of vitamin D.
We store vitamin D inside our liver until it is needed. We have enough storage space of vitamin D for roughly three months before we must get more.
Roles of vitamin D in the body:
- Control of calcium levels in the blood, either by uptake from the intestines (calcium from food) or taken from bone break down in the body, which is why it is also important to get enough calcium in your diet
- Immune support
- Decrease of cellular inflammation
- Supportive role in making new cells and recycling old cells
Since we are now into SPRING and spending more and more time outside in daylight, it is a good opportunity to share a little more about this sunshine vitamin.
If you live where I do, in the Northern hemisphere at or above the 45th parallel, then this is even more timely, as we are just now hitting the time of year where we are close enough to the sun to actually take advantage of it’s UV rays. Between November and April we cannot rely on the sun for adequate vitamin D.
Rule of thumb to take advantage of the sun Spring through Fall to make vitamin D:
Spend 10 minutes with several areas of skin exposed to the sun, every few days. Hands, arms, face, feet, legs all count.
Oh, and you have to actually be outside, sun through a window doesn’t count.
P.s. Don’t worry over the use of sunscreen blocking your UV rays. If you know you will be out in the sun long enough to need sunscreen, then use it! Over-exposure to UV radiation is a far greater risk.
So how do we get vitamin D in the winter?! Well, some of us do not get it, and are deficient most of the winter, or longer. If you do not get out in the sun or your skin is always covered by clothes during the spring and summer months, then you may also be lacking in vitamin D, year around.
Deficiency signs & symptoms:
- Constantly feeling tired, fatigued
- Muscle weakness
- Bone pain
- Bone loss; thin and brittle bones; osteoporosis (in children severe deficiency can cause rickets- soft, weak bones)
- Being sick more often than is usual, or taking longer to heal from illness or injury
If you feel you might be low in vitamin D, you can have a blood test done. Be sure to go over the results with a dietitian or your health care provider.
Good news! You can get vitamin D from other sources besides the sun. There are a select few foods that contain vitamin D naturally, or that have it added to them. It can also be received through supplements.
A note on taking a vitamin D supplement: The only supplement that I recommend generically to anyone is a vitamin D supplement IF *
a) You do not get adequate sun exposure in the summer and do not consume foods with vitamin D on a regular basis; take 500-1000 IU of vitamin D daily, year around.
b) You do not consume vitamin D foods on a regular basis, but you do have adequate sun exposure; take 500-1000 IU of vitamin D daily, only from December to April.
Foods with vitamin D:
- Salmon, tuna, mackerel; other fatty fish
- Egg yolks (small amount)
- Mushrooms (vary in amount)
- Fortified in milk and orange juice
* Since vitamin D is fat-soluble, meaning it is absorbed with fat and stored in the body with fat, it is easier to overdose on than vitamins and minerals that are water-soluble (water-soluble nutrients are flushed out with body fluids).
Weight loss, abnormal heart rate, tissue calcification, kidney stones, can all result from chronically too much vitamin D. This is most likely to happen if you are receiving enough from the sun and food, yet ALSO take a supplement. Another reason to be tested, or supplement only as you know it is necessary.
So there you have it! I hope you learned a little something about our sunshine vitamin.