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Shining the light on vitamin D

Shining the light on vitamin D

The human body requires vitamin D to build strong bones and for good overall health. It plays a vital role in the body’s absorption of calcium. People who don’t get enough vitamin D can develop soft, thin and brittle bones. In children, this condition is known as rickets. In adults, it’s called osteomalacia.

Vitamin D, the “sunshine vitamin,” also plays a role in muscle movement, nerve functioning and in fighting off infection.

It’s been reported that a large proportion of people around the world are deficient in vitamin D. It’s unclear, however, whether this is a true deficiency or a result of baseline levels being set too high. Regardless, there are legitimate concerns about vitamin D deficiency as we have become more aware of the link between sun exposure and skin cancer.

There are very few foods that are naturally high in vitamin D. In the U.S., most of our dietary intake comes from fortified foods, such as milk, some orange juice, and breakfast cereals. Other foods that contain vitamin D include fatty fish, such as salmon, tuna and mackerel; beef liver; egg yolks; and mushrooms.

The Food and Nutrition Board recommends the following vitamin D daily intake:

  • Birth to 12 months – 400 IU
  • Children 1 to 13 years – 600 IU
  • Teens 14-18 years – 600 IU
  • Adults 19-70 years – 600 IU
  • Adults 71 and older – 800 IU
  • Pregnant and breastfeeding women – 600 IU

Do you have a vitamin D deficiency?

The best way to know whether you are getting enough vitamin D is to measure blood levels of a substance known as 25-hydroxyvitamin D. Generally, levels below 30 nmol/L are considered too low for overall health and levels about 125 nmol/L are considered too high.

In general, young people tend to have higher levels than older people; and men have higher levels than women. Non-Hispanic blacks tend to have the lowest levels and non-Hispanic whites have the highest. Groups at risk for not getting enough vitamin D:

  • Breastfed infants, since human milk is a poor source of vitamin D
  • Older adults, because their skin doesn’t make vitamin D as efficiently and their kidneys are less able to convert the vitamin to its active form
  • People with dark skin, because their skin is less able to make the vitamin from sunshine
  • People with disorders such as Crohn’s disease or celiac disease who don’t handle fat properly because vitamin D needs fat to be absorbed
  • Obese people, because body fat binds to some vitamin D, preventing it from traveling through the bloodstream

Too much of a good thing

As much as our bodies need vitamin D, too much of it can be harmful. Signs of vitamin D toxicity include nausea, vomiting, poor appetite, constipation, weakness and weight loss. Because it raises calcium levels in the blood, too much can cause confusion, disorientation and problems with heart rhythms. Excess vitamin D can also harm the kidneys.

Vitamin D toxicity almost always occurs through overuse of supplements. You cannot get too much vitamin D from sun exposure.

Talk to your doctor or healthcare provider

Before starting any supplement program, including vitamin D, talk with your doctor or healthcare provider about the possible risks and benefits. He or she is the best person to help you take good care of your body.

If you don’t have a physician or provider, please call King’s Daughters Care 24/7 service at 1-844-324-2200. We will be happy to help you find a healthcare provider.