#Vitamin D: Facts that can change your life

D Facts

We can’t make vitamins and minerals in our bodies so they must enter with our food, or as supplements or in the case of vitamin D we can make it when UVB rays from sunlight shines on our skin.

Vitamin D is measured in International Units (IU). If you were in the sun for 15 to 20 minutes of unprotected exposure of your skin about 10,000 IU would be made.  However if we use sunblock or cover up our skin with clothing we don’t make any vitamin D.  Yes, there is concern about too much sun causing skin cancer or accelerating aging and anyone who has had skin cancer should not be in the sun. However, short exposure can be beneficial if that is the only source of vitamin D we are getting.

The darker our skin, the less vitamin D we can make because the pigment in the skin blocks the UVB needed to make vitamin D.

 If we stay indoors we get no sun and in the wintertime in cold climates the same is true. As we get older and our skin gets thinner, it is less efficient in making vitamin D. If you`re around 35-40 years old or above, you`re likely losing the ability to make activate vitamin D in your skin, even in the unlikely event that you`re getting adequate UVB sun exposure  We also get less absorption of vitamin D from our food as we age. If you`re overweight, your body requires more vitamin D than if you are not overweight. To get enough vitamin D the sun exposure may be too long to be safe.

How much vitamin D do we need?

The U.S. daily vitamin D dietary allowance is 600 IU for ages 1 to 70 including pregnant or breastfeeding women. For People 71 years and older it is 800 IU.  About 75% of teens and adults in the U.S. are not getting even these basic amounts.  U.S. Dietary allowances are minimum amounts that will prevent deficiency diseases – in the case of vitamin D, rickets is the deficiency disease.  However, dietary allowances are not the optimal amounts that a person may need.  Everyone is different.  And taking or getting the daily allowance does not mean that there is enough vitamin D in the blood.  That is why a blood test is done.  You need to know your level.

Get Tested

So many people are deficient in vitamin D – as many as 1 billion people worldwide. Everyone should get a blood test for vitamin D level.  Because of the widespread deficiency, some doctors are now adding the test to the annual blood work done when we get a physical examination.  Vitamin D is measured in nanograms per milliliter (ng/mL) in the blood.  Some experts say that between 20 and 40 ng/mL is a good level.  In the U.S. 70% of people are under 30 ng/mL, up to 15% are severely deficient at less than 10 ng/mL.  As long as the value is under 100 ng/mL, there is no danger of having too much vitamin D. 

Besides your doctor, you can order tests online and get blood drawn at a local lab, or order a vitamin D home test kit, where you prick your finger, send in the blood, and wait for the results to come back to you.  Make sure you are getting the right test. You must test for 25(OH)D, not 1,25(OH)D. They look similar, but 1,25(OH)D is a measure of kidney function, and is not the test you want for measuring blood vitamin D levels.

Food Sources of vitamin D

So if we can’t get vitamin D from the sun, where do we get it?  The first place is from food.

Fatty fish, egg yolks  (see below) are good sources  but you may have to eat a lot of these foods, especially if you start off deficient. Some foods are fortified with vitamin D such as milk, yogurt, cereal and orange juice. However, the most effective form of vitamin D is D3 (cholecaciferol); some foods are fortified with vitamin D2 (ergocalciferol), a synthetic product which is not absorbed as well.  Vitamins like D and others – as well as minerals, need to be absorbed from our digestive tract into our blood stream before they can work, so the form is important and so is the condition of our digestive tracts (a future blog on this).

Some food values for Vitamin D

1 tsp cod liver oil has 400 to 1,000 IU

3.5 oz salmon, fresh (wild) has 600 to 1,000 IU

3.5 oz salmon, fresh has 100 to 250 IU

3.5 oz salmon, canned has 300 to 600 IU

3.5 oz sardines, canned has about 300 IU

3.5 oz mackerel, canned has about 250 IU

3.5 oz tuna, canned has 236 IU

3.5 oz shiitake mushrooms (fresh) has about 100 IU

3.5 oz shiitake mushrooms (sun-dried) has about 1,600 IU

1 egg yolk has about 20 IU

8 oz fortified milk or yogurt has 100 IU

8 oz fortified orange juice has about 100 IU

3 oz fortified cheese has about 100 IU

If you are not getting enough vitamin D from sunlight and/or food, you may need a supplement.

What Kind of Supplements?

In order to get the best results, it is important what form of the vitamin you use. The best form is an oil-based vitamin D in a gel capsule or liquid. This is because vitamin D dissolves in fat and in that form it can be better absorbed. Take with meals which usually have some fat in the food. Dry preparations, like tablets and capsules are not well absorbed.

Depending on your test results, you may start out at a higher dose and decrease after a month or two. Most experts feel that the goal is to get your level above 30-40 ng/mL then take a lower maintenance amount. When you are deficient, it is recommended to have your blood tested after two to three months of taking the supplement to be sure that your levels are going up. Work with your doctors to find the best plan for you.  Having values too low is very dangerous.

 Interactions with Drugs and Herbs

As is true for any vitamin, mineral or herb, vitamin D can interact with medications. So if you take medications your doctor should have your blood tested for vitamin D level and recommend how much vitamin D you need to take.  Vitamin D may affect blood sugar levels. So if you take medications or insulin that affects  blood sugar, your doctor needs to closely watch your sugar. Medication adjustments may be necessary. Vitamin D may also affect blood pressure. So if you take blood pressure medications they may also need to be adjusted. Some herbs may also affect blood sugar or blood pressure so the same cautions apply to taking vitamin D and herbs.

Symptoms of deficiency and protective effects

You need vitamin D to absorb calcium into your bones, so softening of the bones (osteomalacia) is a result of deficiency. If severe enough, you will have muscle weakness and pain. We know that there is a   protective effect of vitamin D against skin, colon, breast, and prostate cancer. Vitamin D deficiency is associated with an increased blood pressure, cholesterol problems, peripheral vascular disease, coronary artery disease, myocardial infarction, heart failure, and stroke.

Low vitamin D status is often seen with increased upper and lower respiratory tract infections. Vitamin D is very important for good immune system function.  Research shows that people with blood vitamin D levels over 25 ng/mL had a 43% reduced risk of developing type 2 diabetes compared with people with levels under 14 ng/mL.

Decreasing inflammation: Many of the health benefits associated with vitamin D may come from its role in decreasing inflammation. This is good for the heart and for reducing allergies and even reducing cavities in children. Inflammation is associated with many brain diseases.

Brain Health

Reported in 2012, a Journal of Alzheimer's Disease article showed how vitamin D3 may help the body clear the brain of amyloid beta, the main component of plaques associated with Alzheimer's disease. Vitamin D deficiency is also associated with Parkinson’s disease, dementia, and multiple sclerosis (MS). A study in the Journal of the American Medical Association by Harvard researchers found that people with blood levels of vitamin D above 40 ng/mL had a 62% lower risk of developing MS.  Migraines, depression, sleeping problems and fibromyalgia are often linked to vitamin D deficiency.

Every day we are finding out more about the benefits of having adequate and optimal levels of vitamin D.  The National Institutes of Health says that vitamin D deficiency is a world-wide epidemic that has been ignored until recently.  Don’t ignore your health and the health of those you care about.