The need for oral vitamin D supplementation depends on the latitude of the child’s place of residence and the frequency of sunlight exposure as well as the time and timing. This summary chart makes suggestions concerning weight, rather than age to assist with making a clinical decision.
|D3 Dose for children||Body Mass (kg / pounds)|
|Body mass (kg):||5-10||11-20||21-35||36-49|
|Body mass (pounds):||11-22||23-45||46-77||78-109|
|How much strong sun?||Vitamin D3 daily supplement (IU)|
|A little on most days||400||800||1500||2000|
|Lots (outdoor type)||200||400||800||1000|
|Very substantial, daily||0||0||0||0|
Currently, the American Academy of Paediatrics recommends children should have vitamin D levels of at least 50 nmol/L (20 ng/ml). However, as we all know other studies in adults suggest that vitamin D levels should be at least 75 nmol/L (30 ng/ml), and others promote 100 nmol/L (40 ng/ml) -200 nmol/L (80ng/ml), to lower the risk of heart disease and specific cancers.
In this study
The researchers recruited 10 to 17 year-olds to take part in two studies to test the effects of short-term and a long-term supplementation with vitamin D3. For the short-term study, 25 students (10 girls) were given a weekly dose of 14,000 IU for eight weeks. This study was conducted during the summer and early autumn, when the highest vitamin D levels are reached naturally.
For the long-term, 340 students (168 girls) were given either a low dose of vitamin D (1,400 IUs each week) or a high dose (14,000 IUs each week) for one year.
Fuleihan and co-workers report that only children receiving the equivalent of 2,000 IU a day of vitamin D showed the necessary increases in 25(OH)D levels to the 30 ng/ml or 75nmol level considered optimal for adults. Moreover, no evidence of vitamin D intoxication was reported in either the short- or long-term trial.
The authors stated
In children, similarly to adults, the mean 25(OH)D response to each 100 IU of additional oral vitamin D3 is approximately 1 ng/mL (2.5 nmol/L). Therefore, in children with a serum 25(OH)D concentration below 20 ng/mL (less than 50 nmol/L), a vitamin D dose equivalent to 2000 IU per day, preferably as vitamin D3 as opposed to vitamin D2, would be an advisable replacement dose.
The high prevalence of hypovitaminosis D worldwide across all age groups, the fact that many diseases of adulthood are rooted in the paediatric age group, and the safety data available to-date render it quite compelling to modify the current recommendations regarding adequate vitamin D intake not only for adults but also for children.
For children supplementation as suggested above should meet their needs, and as they age a simple blood test may be undertaken to check their status.
 Maalouf J, Nabulsi M, Vieth R, Kimball S, El-Rassi R, Mahfoud Z, El-Hajj Fuleihan G. Short- and long-term safety of weekly high-dose vitamin D3 supplementation in school children. J Clin Endocrinol Metab. 2008 Jul;93(7):2693-701. Epub 2008 Apr 29. View Abstract