Your Daily Dose of D

If you've been hearing about vitamin D a lot lately, you're not alone!  Researchers have long known the important role that vitamin D plays in calcium absorption and calcium balance and that diseases such as rickets, osteomalacia and osteoporosis were caused by a deficiency in vitamin D.  More recently however, vitamin D has become a hot nutrition topic as researchers are finding links between a deficiency and many prominent diseases including cancer (breast, colon, prostate), obesity, cardiovascular disease and chronic inflammation (arthritis, diabetes, multiple sclerosis).

Am I at risk of deficiency?

Data from the National Health and Nutrition Examination Survey (NHANES) revealed that in 2001-2006, approximately 33% of the population was either deficient in vitamin D or at risk of becoming deficient. Vitamin D deficiency is diagnosed by a blood test which measures the amount of serum 25-hydroxyvitamin D. Currently, the target level is set at 30ng/mL, but there is a lot of debate among doctors, researchers, dietitians and others in the medical field to raise the target to 50ng/mL. Those most at risk of vitamin D deficiency are older, non-white females and those with minimal exposure to the sun.

How much vitamin D do I need?

The current Recommended Dietary Allowance (RDA) for vitamin D is 10 mcg for infants and 15 mcg for children and adults. Women who are breastfeeding need 19 mcg per day. Vitamin D is sometimes also expressed as International Units (IU).  A daily intake of 400 IU is recommended for adults. Keep in mind that the RDA was set based solely on intake from food or supplements and does not assume intake from the sun.

How do I get vitamin D?

 

1. Sunlight – One form of vitamin D that the body synthesizes is found on our skin. However, this form is inactive until it is exposed to UV rays. The time of day, cloud cover and latitude can affect the amount of sunlight absorbed. Some research suggests that only 5-15 minutes between the hours of 10 a.m. and 3 p.m. during the spring, summer and fall may be effective and safe for people with skin that is prone to burning. Brief exposures to the sun are thought to equal about 5 mcg of vitamin D.
2. Diet – Consuming foods that are high in vitamin D can help prevent deficiency. Key food sources include fatty fish such as salmon (1 oz = 3.5 mcg), canned tuna (3 oz = 4 mcg), egg yolks (1 yolk = 1 mcg), beef liver (3 oz = 1 mcg), and irradiated mushrooms (½ cup = 1 mcg). Many fortified foods such as milk (1 c = 3 mcg), cereal (1 c = 1 mcg) and orange juice (1 c = 2.5 mcg) are also good sources.
   
3. Supplements – A daily multivitamin or supplement is another way to ensure you are getting enough vitamin D and they can be purchased without a prescription. Look for one that provides around 10-15 mcg or 200 IU of vitamin D3.

   

 

Healthfully Yours,

Meghan