Current intake recommendations of 200 to 600 IU vitamin D per day may be insufficient for important disease outcomes reduced by vitamin D.
Introduction: This study assessed the benefit of higher-dose and higher achieved 25-hydroxyvitamin D levels [25(OH)D] versus any associated risk.
Methods and results:
• Based on double-blind randomized control trials (RCTs), eight for falls (n = 2426) and 12 for non-vertebral fractures (n = 42,279), there was a significant dose-response relationship between higher-dose and higher achieved 25(OH)D and greater fall and fracture prevention.
• Optimal benefits were observed at the highest dose tested to date for 700 to 1000 IU vitamin D per day or mean 25(OH)D between 75 and 110 nmol/l (30-44 ng/ml).
• Prospective cohort data on cardiovascular health and colorectal cancer prevention suggested increased benefits with the highest categories of 25(OH)D evaluated (median between 75 and 110 nmol/l).
• In 25 randomized control trials, mean serum calcium levels were not related to oral vitamin D up to 100,000 IU per day or achieved 25(OH)D up to 643 nmol/l.
• Mean levels of 75 to 110 nmol/l were reached in most randomized control trials with 1,800 to 4,000 IU vitamin D per day without risk.
• Our analysis suggests that mean serum 25(OH)D levels of about 75 to 110 nmol/l provide optimal benefits for all investigated endpoints without increasing health risks.
• These levels can be best obtained with oral doses in the range of 1,800 to 4,000 IU vitamin D per day;
• Further work is needed, including subject and environment factors, to better define the doses that will achieve optimal blood levels in the large majority of the population.
Source: Osteoporosis International, Dec 3, 2009. PMID: 19957164, by Bischoff-Ferrari HA, Shao A, Dawson-Hughes B, Hathcock J, Giovannucci E, Willett WC. Centre on Aging and Mobility, Department of Rheumatology and Institute of Physical Medicine, University Hospital Zurich, Switzerland. [E-mail: Heike.Bischoff@usz.ch]