Vitamin D---Should You Be Taking More of this Vitamin?

"In a recent issue of the Archives of Pediatrics and Adolescent Medicine, Gordon and her colleagues found that 40 percent of infants and toddlers tested below average for vitamin D. In a previous study, Gordon and fellow researchers discovered that 42 percent of adolescents were vitamin D deficient."

"The prevalence of vitamin D deficiency varies according to the population studied. Age, latitude, season, race, and lifestyle all play important roles in vitamin D status. Clearly, homebound or institutionalized persons have a high prevalence of vitamin D deficiency. In one study, the prevalence ranged from 38% in nursing home residents to 54% in housebound community dwellers.11

Less recognized is the frequency of vitamin D deficiency in healthy African Americans, regardless of age, and in healthy adolescents and young adults. The third National Health and Nutrition Examination Survey (NHANES III) included more than 18,000 adolescents and adults living at latitudes of 32 or more degrees north and found that vitamin D insufficiency was very common, although a severe deficiency was not.12 The lowest vitamin D levels were in African Americans, most likely because of decreased skin synthesis due to dark pigmentation. A study of 1,546 healthy African American and 1,426 white women between ages 15 and 49 years (participants in NHANES III) showed that 42% and 4%, respectively, had a mild to moderate vitamin D de-ficiency (<15 ng/mL [37 nmol/L]).13 Twelve percent of the African American women and less than 1% of the white women had a severe deficiency (<8 ng/mL [20 nmol/L]).

Reinforcing the observation that latitude and season play a role in vitamin D deficiency, vitamin D levels were measured in healthy men and women living in Boston at the end of summer and winter.14 Low vitamin D levels (<20 ng/mL [50 nmol/L]) were found in 30% at the end of winter and in 11% at the end of summer. Surprisingly, 32% of the youngest age-group (18 to 29 years) had vitamin D insufficiency at the end of winter as compared with 16% in the oldest age-group (>50 years). This discrepancy may be because older persons take a multivitamin that provides vitamin D."

So how much should you take?

According to Mayo Clinic:

"The National Academies of Sciences currently recommends 200 international units (IU) of vitamin D for children and adults up to age 50 and 400 to 600 IU for adults older than age 50. However, researchers now question whether these levels are adequate for optimal health.

So, how much vitamin D is enough? There's still much debate about what the recommendations should be. But most researchers agree that a daily intake of 800 to 1,000 IU would benefit many people — especially those at increased risk of vitamin D deficiency, including:

• Babies who are exclusively breast-fed
• Older adults
• People with limited sun exposure
• People with darker skin
• People with fat malabsorption, such as due to celiac disease, Crohn's disease, pancreatic insufficiency, liver disease or cystic fibrosis"

How much do I take?  Currently I am taking 1000 units/day.  But is this necessary?  What do you think?

Do you take Vitamin D on a regular basis?