Vitamin D

Dr. Margit Lister with Wasatch OBGYN clears up the confusion about Vitamin D.


There seems to a lot of information about Vitamin D in the news. What’s great news is that we are expanding our knowledge base immensely on the possible benefits of vitamins. Unfortunately, not all reports are adequate to hang your hat on…yet.

Let’s first talk a little about the sunshine vitamin.

Vitamin D is a fat-soluble vitamin. It is found naturally in very few foods but is produced within your body when you skin is exposed to sunlight.

It is thought that about 50% of the population above the 42nd degree latitude will be deficient in vitamin D, especially during the months of November thru February. This imaginary line basically runs thru Salt Lake City. If you are north of Salt Lake, you’re likely in need of vitamin D, if you are south of SLC and in the sun, you may just be low.

In order to get adequate vitamin D from the sun alone, you would need to sunbath for about 5-30 min between the hours of 10 am to 3 pm without sunscreen (because a sunscreen of greater than 8 SPF blocks your skins ability to synthesis Vitamin D) at least twice a week exposing your arms, legs, or back. For the record, I am NOT recommending that you expose yourself to the sun for 30 min without sunscreen! But this is what is needed to get adequate vitamin D from the sun only.

Our increase in the use of sun screen, cloud cover, smog, times indoor and time of day for sun exposure has caused an alarming amount of people to be deficient in vitamin D. Those mostly affected are at the extremes of age; newborns who are partially or exclusively breastfed and those over the age of 50. Darker skinned individuals are at greater risk than our fair skinned friends.

Where else can you find Vitamin D?

Foods that naturally contain vitamin D are Oily fish; cod, tuna, mackerel, and salmon. Fortunately, Vitamin D has been added to milk, fortified OJ, and cereal products since the 1930’s. It is also available as a vitamin supplement, which seems to be the safest and simplest way to obtain vitamin D. Infants should consume 400 IU/day starting within the first few days of life while adults can consume up to 1000 IU/day.

How do you know if you are vitamin D deficient? What are the symptoms?

Unfortunately, there are no real symptoms of a vitamin D deficiency. Lack of vitamin D use to cause Rickets in children but since the supplementation in foods, this is rare in the United States. Some individuals may have weak muscles or bone pain but the deficiency usually goes unnoticed.

A simple blood test performed by your doctor (25-OH vitamin D) can determine if you are deficient, inadequate, or adequate.

If you are taking steroids, weight loss drugs that limit fat metabolism or the seizure medication, these could limit your ability to absorb vitamin D from your diet. Obesity decreases your body’s ability to absorb vitamin D.

Can I take too much vitamin D? YES!!

Vitamin D is a fat soluble vitamin, which means it is stored in fat and you can become sick if you take too much of it. Symptoms of too much vitamin D are nausea, vomiting, poor appetite, constipation, weakness and weight loss. It can also increase the amount of calcium in your blood causing confusion and an irregular heart rate. Vitamin D toxicity is rare.

What does vitamin D do?

Vitamin D is known to maintain bone strength and integrity.

Supplementations with vitamin D and calcium have statistically decreased a person’s risk of falls and fractures as they age (elderly women age 62-85yrs of age).

Cancer– this is a new connection with Vitamin D. It has been noted that people with higher levels of vitamin D have a decreased risk of cancer. Though other studies show supplementation with Vitamin D did not lower a person’s cancer risk for colon or breast cancer. The evidence is conflicting. There are several clinical trials underway which should shed some clear recommendations for vitamin D, but as of right now, its addition to your diet is unlikely to hurt and may help!

Cardiovascular disease – Low levels of vitamin D are associated with high blood pressure, diabetes, and cardiovascular disease. Again, vitamin D was supplemented for people and it did not seem to lower their risk of cardiovascular disease.

BUT… if you look at all the reasons why people died, people who had higher levels of vitamin D lived longer. So again, Vitamin D seems to help thought supplementation has not been proven to prevent disease.

What we know:

Vitamin D is important in bone health
Vitamin D inadequacy affects a large population
Vitamin D has many health benefits beyond bones
The recommendation for vitamin D supplementation by the RDA is low.

What we don’t know:

Will it cure cancer, heart disease, preeclampsia etc.
How much vitamin D we need to be healthy.

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