What Happens If You Don't Get Enough Vitamin D?

Roughly half of all Americans — older adults in particular — don’t get enough vitamin D. What are the implications of this? This nutrient is essential to our muscles, bones and immune systems. New research links low levels of vitamin D to a growing list of health problems, including heart disease and cancer.

Low Vitamin D Can Mean Trouble
Vitamin D helps form and strengthen bones by allowing the body to absorb calcium. Without adequate vitamin D, bones become thin and brittle. The vitamin also helps our muscles and immune system function.

A deficiency in vitamin D is a concern because the nutrient appears to play a role in several serious medical conditions, including:

  • Cancer — Research suggests that vitamin D may help protect against breast, prostate and colon cancer
  • Diabetes — Vitamin D may reduce the risk for type I diabetes in children
  • Heart disease — Low blood levels of vitamin D may be related to cardiovascular disease
  • Osteoporosis — Low levels of vitamin D have been tied to osteoporosis and hip fractures in older women

With all of these findings, researchers point out that further investigation is needed, but it is projected that the incidence of many of these diseases could be reduced by 20 to 50 percent or more, if the occurrence of vitamin deficiency and insufficiency were eradicated by increasing vitamin D intakes.

What Causes Low Levels of Vitamin D?
Experts suspect there are two reasons why people have trouble getting enough vitamin D. One is that few foods contain the vitamin naturally. Another is that a common source of vitamin D is ultraviolet radiation from the sun, which penetrates uncovered skin and converts chemicals in the body into the vitamin. While traditionally many of us got our vitamin D from sunlight, the risk for skin cancer has led many people to limit their time outdoors or to wear sunscreen, which often blocks vitamin D-producing rays.

Ensuring You Get Enough
The government currently recommends that healthy people get the following amounts of vitamin D each day:

  • Children and adults ages 50 and younger: 200 international units (IU)
  • Adults ages 51 to 70: 400 IU
  • Adults ages 71 and older: 600 IU

It is important to note that, according to the University of California Scientists Panel, new evidence indicates that, in order to prevent or substantially reduce the incidence of breast and other cancers, type I diabetes and multiple sclerosis, there is need for new public health policy to raise the intake of vitamin D closer to 1,000 to 2,000 IU per day for adults and teenagers, and 1,000 IU for children ages 1 to 12. This is the current upper limit of the National Academy of Sciences, Institute of Medicine, Food and Nutrition Board.

The best way to get your dose of D is to consume those foods that are rich in the vitamin. Milk, yogurt, orange juice and boxed cereals often have vitamin D added. Salmon, tuna and mackerel also are good sources. Find healthy recipes to help boost your vitamin D intake.

Experts don’t recommend taking high doses of the vitamin as a supplement or forgoing sunscreen and other healthy sun practices. If you worry that you may not be getting enough vitamin D, talk with your doctor.

For More Information
To learn more about Sharp's nutrition services or to find a Sharp-affiliated physician, search for San Diego doctors or call 1-800-82-SHARP (1-800-827-4277), Monday through Friday, 8 am to 6 pm. To find general information about nutrition, read the Nutrition News archive.