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Thursday, March 11, 2010

All About Vitamin D

All About Vitamin D

By GNC Health Buzz | 03/01/2010 
WHAT IS VITAMIN D?

Vitamin D is a fat-soluble vitamin that promotes the body's absorption of calcium which is essential for the normal development and maintenance of healthy teeth and bones.  Also known as the "sunshine vitamin," vitamin D is manufactured by the body after being exposed to sunshine.


HOW MUCH DO WE NEED?
Children: The American Academy of Pediatrics recently doubled its recommendation for the minimum amount of vitamin D that infants, children and teens should get daily.  The new recommendation is to get at least 400 IU (International Units).  It's important to talk to your doctor about your child's vitamin D needs.
Adults: The current recommended daily intake is 200 IU for those ages 19 to 50, 400 IU for those ages 51 to 69 and 600 IU for those older than 70.
However, research supports the growing consensus that we need to consume a lot more - up to 1,000 IU to keep blood levels of vitamin D where they need to be.  Some doctors recommend even higher levels so it's important to talk to your doctor about your current D levels and how much he or she recommends for you.


WHAT ARE THE BENEFITS OF VITAMIN D?
In both children and adults vitamin D is critical for teeth and bone health.  It is essential in helping your body absorb calcium and helps regulate calcium and phosphate levels for strong, healthy bones and teeth.  Vitamin D has been linked to the prevention of osteoporosis.
Vitamin D can also act as a hormone and is vital for blood vessel health and even brain function.
Several recent studies have suggested that vitamin D may also play a critical role in heart, respiratory and breast health, and immune system function.


WHAT ARE THE RISKS OF VITAMIN D DEFICIENCY?
In adults, a blood level less than 50 nmol/L is considered to be deficient in vitamin D.  But in children, researchers often consider 25 nmol/L or less as deficient.  Your doctor can check yours and your children's current levels.
When the body is deficient in vitamin D, it is unable to properly regulate calcium and phosphate levels.  If the blood level of these minerals becomes too low, other body hormones may stimulate the release of calcium and phosphate from the bones to the bloodstream to elevate blood levels.
Adults: In adults, vitamin D deficiency may have a negative impact on bone and heart health.
Children: Too little vitamin D can cause rickets, a progressive softening and weakening of the bones' structure.


WHO IS AT RISK OF VITAMIN D DEFICIENCY?
Research suggests that 80% of people living in the United States don't get enough vitamin D, and some individuals are at an especially high risk of deficiency, including:
~Older Americans - aging skin loses the ability to convert vitamin D to an active form
~Homebound individuals
~People in northern latitudes, especially during winter months - The further you are located from the equator, the less direct sunlight you have and the weaker the UV rays that reach you will be.  Season, latitude, time of day, cloud cover and smog also all affect the amount of potential UV ray exposure
~People who cover their bodies for religious reasons
~Those whose occupations prevent them from getting sun exposure
~People who have dark skin such as African Americans and Latinos - dark pigmented skin does not produce as much of the vitamin from sunlight
~People who don't drink milk or eat dietary sources of vitamin D
~People who have reduced liver or kidney function
~Pregnant women - Expecting and lactating mothers should take special care to ensure they aren't vitamin D deficient.  Human milk contains little vitamin D as it is, and women who have vitamin D deficiencies provide even less of the nutrient to their newborns
When it comes to children, according to a recent study at Children's Hospital Boston, over 300,000 American children may be deficient in vitamin D


WHAT ARE SOURCES OF VITAMIN D?
1. Sunlight - We can obtain vitamin D through skin exposure to sunlight.  According the National Institutes of Health, 10-15 minutes of sunshine three times weekly is adequate to produce the body's requirement of vitamin D.  However, because of limited sunlight exposure in most of the U.S. during winter and the widespread use of UV-protective sunblock, very few people can obtain adequate vitamin D levels with sun exposure.
2. Diet - Vitamin D occurs naturally in several foods, such as fish, cod liver oil and fortified milk, juice and cereals.  Dairy products such as cheese, butter, cream and some yogurts also contain vitamin D.
3. Supplementation - There are many vitamin D supplements on the market available in a range of IU (International Unit) levels.  Supplements are a great alternative if you are not getting adequate amounts through sunlight or in your diet, but as always, talk to your doctor about the right levels and the right sources of vitamin D for you.