Vitamin D is coming up more often lately in the health care community.

Here’s what you need to know about this increasingly buzzworthy — but often confusing — essential vitamin.

Q: What is vitamin D?

A: It is often called the sunshine vitamin because the body produces it when the skin is exposed to sunlight. It is rarely present in large amounts in food, even fortified foods.

Q: Are you getting enough vitamin D?

A: If you live in Western Washington, the answer is likely no, especially if you’re older than 65 or have health problems.

Q: Why are so many people deficient?

A: In Western Washington, we are particularly sun-deprived because of our climate and short winter days.

Q: Why do we need it?

A: Scientists have known for a long time that vitamin D is essential for healthy bones. New research suggests it could decrease the risk of certain types of cancer, diabetes, multiple sclerosis, autoimmune diseases, heart disease, osteoporosis and depression.

Q: How much do I need?

A: Though most multivitamins contain the recommend daily allowance of 200 to 600 international units (IU) depending on age, many doctors are encouraging patients of all ages to take more, sometimes more than 2,000 IU.

Dr. Steven Grant, a family practice doctor with the Providence Physician Group in Marysville, recommends a 1,000 IU daily supplement to all his adult patients, even if they are already taking a daily multivitamin.

Q: Can I get tested?

A: Yes. In fact, Grant recommends a simple blood test to check vitamin D levels for everyone older than 65.

Older people, people with darker skin, obese people and infants fed only breast milk are more at risk of deficiencies.

Q: Should I expose my skin to the sun?

A: The American Academy of Dermatology issued a statement in 2009 saying there is no safe threshold for sun or indoor tanning exposure and that people should seek dietary and supplemental sources of vitamin D instead of going outside without sunscreen.

Getting your D

Birth to 12 months: 200 IU

Children 1 to 18: 200 IU

Adults 19 to 50: 200 IU

Adults 51 to 70: 400 IU

Adults 71 years and older: 600 IU

Pregnant or breast-feeding: 200 IU

These recommended daily intakes for vitamin D, in international units, come from the National Academies, which sets the official recommended amounts used in nutritional labeling.

Later this year, the group is expected to revise the recommended levels, last updated in 1997.

Recommended maximum intake limits are 1,000 IU for age 0 to 12 months and 2,000 IU for all other ages.