Learn why vitamin D is important to good health

Published 1:21 pm Monday, December 29, 2008

It’s easy to become D-deficient. According to the latest research, many of us are low in the vitamin, which is needed in adequate amounts for good health.

Test your knowledge of vitamin D deficiency with this quiz.

1. What jobs does vitamin D perform in the body?

a. Strengthens bones

b. Improves heart health

c. Regulates immunity

d. All of the above

2. Vitamin D behaves like a hormone in the body. True or false?

3. An increased risk of vitamin D deficiency is linked with:

a. Outdoor jobs

b. Northern climates

c. Slender physique

d. Younger age

4. Which condition is not associated with low vitamin D levels?

a. Type 2 diabetes

b. Rheumatoid arthritis

c. Ulcerative colitis

d. Multiple sclerosis

5. An excess of vitamin D leads to osteoporosis. True or false?

6. The recommended amount for all adults is 200 International Units (IU) a day. True or false?

7. The best food source of vitamin D is:

a. Fresh-squeezed orange juice

b. Raw milk

c. Seafood

d. Hot oatmeal

Answers

1. d. Vitamin D has many roles. It strengthens teeth and bones, fosters heart health and improves immunity to infections. Early research suggests that it may also reduce the risk for cancers of the colon, breast, ovaries and prostate.

2. True. Uniquely different from any of the other vitamins that your body requires, vitamin D acts like a hormone, helping relay chemical messages around the body. This hormone-like activity makes vitamin D invaluable in many health-related tasks.

3. b. Growing evidence suggests that almost everyone is at risk for vitamin D deficiency. Factors that elevate that risk include indoor jobs, northern climes, older age and obesity. Dark skin, digestive or kidney disease, and exclusive breastfeeding in infants can pose additional risks.

4. a. A deficiency of vitamin D has been linked to type 1 diabetes, the insulin-dependent type that usually starts in childhood. Autoimmune disorders such a rheumatoid arthritis, ulcerative colitis, Crohn’s disease and multiple sclerosis are also associated with lower levels of vitamin D.

5. False. A long-term deficiency of vitamin D can result in osteoporosis, the brittle-bone disease that can lead to broken hips. A shortage may also result in bone diseases such as rickets in children and osteomalacia in adults.

Excess amounts of vitamin D may result in nausea, vomiting, constipation, confusion, high blood levels of calcium and irregular heart beats. For safety, the Institute of Medicine (IOM) recommends an upper limit for adults of 2,000 International Units (IU) per day.

6. False. Current recommendations from the IOM call for 200 IU a day for people from birth through age 50, 400 IU for those 51 to 70 and 600 IU for those older than 70. But some experts say that optimal amounts are closer to 1,000 IU daily. Talk to your provider about the amount of vitamin D from food and supplements that’s right for you.

7. c. Salmon, mackerel, tuna and sardines are rich in vitamin D. Other good sources include fortified forms of milk, soy milk, margarine or orange juice as well as some ready-to-eat cereals.

Another tip: Your skin can make vitamin D in the presence of sunshine. Limit exposure to 10 or 15 minutes twice a week to your face, arms, legs or back. Afterwards, be sure to apply sunscreen to prevent skin cancer and aging.

For more information: Office of Dietary Supplements, ods.od.nih.gov.

Contact Dr. Elizabeth Smoots, a board-certified family physician and fellow of the American Academy of Family Physicians, at doctor@practicalprevention.com. Her columns are not intended as a substitute for medical advice or treatment. Before adhering to any recommendations in this column consult your health care provider.

&Copy; 2008 Elizabeth S. Smoots