Vitamin D

Mushrooms naturally contain Vitamin D

By Daphne Higgins
Special to GetFitMississippi.com

Dorothy Jasper of Jackson, a retired registered nurse, understands the importance of including vitamin D in her diet.

During nursing training, she learned vitamin D is essential to a healthy life. Now she's making sure her 1-year-old grandson, Jarrett Vernon Jasper Jr., gets the proper amount.

"He's drinking whole milk now. His pediatrician has not recommended that he take anything else at the moment. I know that making sure he receives the proper amount of vitamin D will ward off a lot of health problems later," she said. "Why anyone would refrain from getting vitamin D is a complete mystery to me."

Though reports vary on the exact numbers, experts report vitamin D deficiency is highly prevalent in the United States. The National Institutes of Health reports the adequate international unit intake for vitamin D is 200 for persons up to age 50; 400 for persons 51-70 and 600 for those 70 and older.

Vitamin D is synthesized or produced naturally when skin is exposed to the sun's ultraviolet rays.

February has been named Vitamin D Deficiency Month. The recognition comes as an effort by the UV Foundation in Virginia to raise awareness regarding vitamin D deficiency and the negative health effects that can occur.

"There have been recent studies that have expanded topics based on solid research showing vitamin D can reduce the risk of some cancers and other health issues," said Dr. Patrick Gregory, who specializes in homeopathic medicine and works as a health educator for Central Mississippi Health Services in Jackson.

"The general population is unaware of the recent research, and many health professionals have not paid much attention to it either. We need to properly communicate that vitamin D intake is necessary and especially important within the African-American community, especially for those of a darker skin tone who have a more difficult time getting the proper amount of sunlight."

One report that supports Gregory's comments - "Vitamin D and African Americans" published in the Journal of Nutrition (April 2006) - also concludes vitamin D insufficiency is more prevalent among many African Americans because pigmentation reduces vitamin D production in the skin.

The report says it is becoming more apparent that vitamin D protects against other chronic conditions, including cardiovascular disease and diabetes, all of which are as prevalent or more prevalent among blacks than whites.

"It's easy for it to go under the radar," said Dr. Chad Rhoden, clinical and research director in the Department of Preventive Medicine at Baptist Medical Center. To detect deficiency, Rhoden recommends getting a blood test that checks for 25-hydroxyvitamin D, a precursor to the active form of vitamin D.

Rickets and ostemolacia are classic conditions that can result from vitamin D deficiency. Rickets causes skeletal deformities. Ostemolacia causes weak bones and muscles. Fortified milk has made rickets a rare condition in America.

Some studies point out vitamin D can maintain a healthy immune system, and inadequate levels can predispose people to hypertension, Rhoden said. Higher levels of vitamin D are linked to lower rates of breast and colon cancer. Some research also shows fewer falls among elderly who have adequate levels of vitamin D.

Vitamin D's "major function is to maintain normal blood level of calcium," Rhoden said. Without it, bones become thin and brittle.

Vitamin D deficiency can occur for a variety of reasons. Rhoden said people at risk include those who live in regions with little sun exposure, especially during the winter months or in regions with lots of smog; babies who are exclusively breast-fed; people with absorption problems in their digestive tract; those with milk allergies or who are lactose intolerant; strict vegetarians and homebound individuals.

Older adults' skin may not be able to synthesize vitamin D, leading to hip fractures. Using sunscreen that blocks the sun's ultraviolet rays can affect levels, and Rhoden said skin pigmentation plays a role regardless of race.

Though Mississippi gets its fair share of sunlight, those who work all day in an office and only come out at night or those who sleep in the day and work at night could be at risk, Rhoden said.

To combat the deficiency, experts recommend sun exposure, dietary changes and supplements.

One controversial method to acquire vitamin D is through ultraviolet light from tanning beds - a method most dermatologists denounce.

Fortified foods such as milk, cheese, ready-to-eat breakfast cereals, salmon, sardines, tuna and whole eggs are top sources.

"It's always better to get it through dietary habits," Rhoden said. Taking too many supplements could lead to toxic levels, and too much sun exposure has other adverse effects.

Gregory said the toxic level of vitamin D is thought to be about 40,000 IU taken daily over time. Most supplements available to the public are 400 IU or 1,000 IU. Gregory and Rhoden predict the suggested IU will one day increase.

One vegetable that is a good source of vitamin D is the mushroom. Preliminary research suggests ultraviolet light may boost levels of vitamin D in mushrooms, according to the Mushroom Council, an organization composed of fresh market producers and importers.

The natural process of "enriching" mushrooms by briefly exposing mushrooms grown in the dark to light for five minutes may boost existing vitamin D levels from 15 IU to as much as 100 percent of the daily value of 400 IU.

The industry is investigating ways to make mushrooms enriched with vitamin D through light enhancement commercially available.

"Mushrooms are the only natural fresh vegetable or fruit that contains vitamin D.

"Mushrooms contain ergosterol - a plant sterol - that is converted to vitamin D when exposed to the right amount of sunlight," said Mona Calvo, a nutritionist with the Food and Drug Administration.