The study's lead researcher Ghada El-Haff Fuleihan pointed out that the benefit from a 2,000 IU daily intake would not only be safe, and important for the health reasons cited, but that it would be necessary to dose at that level in order to achieve desirable vitamin D levels.*

The recommended "Adequate Intake" (AI) levels** of vitamin D for children, and adults, is based on a guidelines established by the U.S. Institute of Medicine of the National Academy of Sciences. In 2003, the American Academy of Pediatrics (AAP)  set 200 IU per day as the recommended AI for all infants and children, including adolescents . In 2008,  based on a wide body of evidence, the American Academy of Pediatrics doubled the amount of vitamin D it recommends for infants, children and adolescents  to 400 IU per day.

The current recommended AIs for vitamin D, have long been scrutinized by proponents of higher vitamin D intake both in children, and in adults.The recommended intakes were set to prevent severe deficiency of vitamin D, and the prevention of rickets and bone disease. However, vitamin D deficiency is now considered to be an epidemic. Rickets is not an uncommon condition here in the U.S and around the globe-even in the sunniest of climes. (2)

Numerous clinical studies that at least 400 to 1,000 IUs were necessary for infants to “achieve a healthy 25(OH)D level of greater than 30 ng/ml” and correct vitamin D deficiency at birth. (2) Similar studies concluded that oral pharmacological doses of 2,000 to 4,000 for 3 to 6 months, or periodic single oral doses of 200,000 IUs were necessary to reverse rickets. (2)

Data on more than 6,000 children, ages one to 21, collected by the National Health and Nutrition Examination Survey (NHANES) 2001-2004 concluded that "Overall, 9% of the pediatric population, representing 7.6 million US children and adolescents, were 25(OH)D deficient and 61%, representing 50.8 million US children and adolescents, were 25(OH)D* insufficient."(3) The 2009 NHANES study concluded that low levels of vitamin D deficiency were associated with higher parathyroid hormone levels, a marker of bone health, higher systolic blood pressure, and lower serum calcium and HDL (good) cholesterol levels, which are key risk factors for heart disease.



The NHANES study authors recommended that pediatricians should routinely screen high-risk children for vitamin D deficiency, and that parents should ensure that their kids get adequate amounts of the vitamin through a combination of diet, supplements, and exposure to sunlight.

* The 25-OHD (25-hydroxyvitamin D) serum marker, easily obtainable through a blood test, * is the vitamin D marker that reflects biological activity, and is widely used to evaluate serum vitamin D levels.

**Dietary Reference Intakes (DRIs) are a comprehensive set of nutrient reference values set up by the Food and Nutrition Board (FNB) through a review process overseen by the Institute of Medicine (IOM) of the National Academies, which is an independent, nongovernmental body in the United States. Dietary Reference Intakes or DRIs is an umbrella term that describes types of nutrient intake reference values. They include: 

• Recommended Dietary Allowance (RDA):average daily level of intake sufficient to meet the nutrient requirements of nearly all (97%-98%) healthy people.
• Adequate Intake (AI): established when evidence is insufficient to develop an RDA and is set at a level assumed to ensure nutritional adequacy.
• Tolerable Upper Intake Level (UL): maximum daily intake unlikely to cause adverse health effects

1. Short- and long-term safety of weekly high-dose vitamin D3 supplementation in school children. Maalouf J, Nabulsi M, Vieth R, Kimball S, El-Rassi R, Mahfoud Z, El-Hajj Fuleihan G.                                                             J Clin Endocrinol Metab. 2008 Jul;93(7):2693-701. Epub 2008 Apr 29.

2. Resurrection of vitamin D deficiency and rickets
Michael F. Holick             J. Clin. Invest. 116(8): 2062-2072 (2006).

3. Prevalence and associations of 25-hydroxyvitamin D deficiency in US children: NHANES 2001-2004. Kumar J, Muntner P, Kaskel FJ, Hailpern SM, Melamed ML.
Pediatrics. 2009 Sep;124(3):e362-70. Epub 2009 Aug 3.