Guest Blog: Vitamin D - What you need to know

This blog post was written by Marina Vigil, a California State University, Long Beach Dietetic Intern.  She is one of my former students with whom I had the pleasure of working with during her self-select rotation.  Thank you for sharing your knowledge with us, Marina!

Photo credit:  pittaya (Flickr)

Vitamin D: What Do You Need To Know?

Vitamin D has been receiving a lot of attention lately. Why? Vitamin D is a fat soluble vitamin that has long been known to be an important part of the body’s bone growth and maintenance by helping to maintain proper levels of calcium and phosphorus. But now research suggests that Vitamin D may be involved in the treatment and/or prevention of many diseases including diabetes, multiple sclerosis, and some cancers. Even though some of this research is inconclusive, it is still important to get adequate Vitamin D.

Where can I get my Vitamin D?

Unlike most other nutrients, your body can make all the Vitamin D that you need with the help of sunlight.  This is why Vitamin D is sometimes called the sunshine vitamin. On a clear, sunny day, most people only need to expose their hands, face and arms (without sunscreen) for 5 to 30 minutes a few times a week. However, due to the risk of skin cancer, the American Academy of Dermatology does not recommend getting your Vitamin D from light, either naturally from the sun or artificially from indoor tanning. If you do get your Vitamin D from light, be aware of the risk of sun damage.  Wear sunscreen outdoors and limit use of tanning beds to decrease your risk of sun damage.

The best way to get your Vitamin D is through a healthy diet. Not many foods are naturally rich sources of Vitamin D, but the good news is that it is still easy to get the recommended amounts of Vitamin D! Because it is so important, many foods, such as dairy products, juices, and cereals, are fortified with Vitamin D. Tofu and other soy products are also often fortified. In addition, eggs and fatty fish, such as salmon, tuna, and mackerel, are natural sources of Vitamin D.   Try to include a variety of these foods to maintain an adequate amount of Vitamin D.

Who is at risk of deficiency?

Unfortunately, research shows that many people are not getting enough of this vital nutrient, even in areas with plenty of sun. With our busy lifestyles nowadays many people spend the sunniest part of the day inside and are missing out on Vitamin D production. The elderly are also at higher risk for deficiency because the body makes less Vitamin D with age. So, how do you know if you are deficient? The answer is you don’t unless you get tested. You should talk to your doctor about getting tested.  It’s important to know that your levels will be lower in the winter.

Can I have too much Vitamin D?

Now, some people say that you can never have too much of a good thing, but that is not always true. Although vitamin D is great for your health, too much vitamin D can have toxic effects. High levels of vitamin D can cause high levels of calcium known as hypercalcemia. But the good news is that you cannot get vitamin D toxicity from the sun. If you are in the sun too long, your body will stop making Vitamin D and will break it down instead to prevent toxic levels. Vitamin D toxicity is usually caused by taking supplements.  For this reason, I would not recommend taking supplements unless you know you are deficient. Then, you and your doctor or dietitian can determine whether a supplement is right for you.

For more info on the Institute of Medicine's dietary reference intakes for vitamin D, click here.

Do you know your Vitamin D level? What Vitamin D rich foods do you enjoy?