New position paper focuses on optimizing vitamin D levels in global populations

A position paper prepared on behalf of the International Osteoporosis Foundation (IOF) Vitamin D Working Group summarises the problem of vitamin D deficiency and public health approaches to its prevention on a global scale. It addresses key issues such as global differences in vitamin D status, methodological issues with testing, guidelines, screening, supplementation and food fortification.

The work was published in the journal Osteoporosis International.

Professor Bess Dawson Hughes, professor of medicine at Tufts University School of Medicine, senior investigator in the endocrine division at Tufts Medical Center and senior author of the paper, said: "Vitamin D levels in populations vary around the world and are influenced by a number of factors such as diet, skin pigmentation, clothing, latitude, effective sun exposure and supplement use.

"We know that vitamin D is important for overall health, and that severe vitamin D deficiency in some people can lead to serious health problems such as rickets or osteomalacia. In these patients, vitamin D levels need to be restored urgently. However, at the public health level, the role of vitamin D supplements requires different considerations. Here, the goal is to maintain vitamin D levels high enough to reduce the risk of overall health problems."

Based on recently published papers of the European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases, the position paper "Optimising vitamin D status in global populations" concludes:

• Maintaining adequate vitamin D status at the population level is achieved preferably through diet and lifestyle. Food fortification, as practiced in some countries, may provide an alternative route to optimising vitamin D status. Another approach to meeting vitamin D requirements is supplementation at moderate daily doses. It is important that any intervention takes into account individual population characteristics, including, for example, habitual calcium intake.
• Based on the current evidence base, there is insufficient justification for screening for vitamin D deficiency in the general population.
• Screening and/or routine supplementation may be appropriate in high-risk groups, such as older adults in nursing homes and people with pigmented skin living in northern latitudes.
• At the individual patient level, where clinical symptoms suggest vitamin D deficiency, testing would likely be indicated, along with a more aggressive approach to restoring vitamin D levels.
• When a supplement is recommended by a healthcare professional, it should be in the form of a licensed product to ensure consistency between the prescribed and actual dose. Due to evidence showing an increased risk of falls and fractures, bolus doses are generally not recommended unless there is a specific need for rapid correction.

The authors also point to clear gaps in the documentation of vitamin D deficiency worldwide, describing key methodological issues such as assay variability and lack of standardization of reporting. For future studies on the epidemiology of vitamin D and to strengthen future guidelines, the authors recommend that standardized measures of 25(OH)D, as defined by the Vitamin D Standardization Program, be reported in all studies and publications.

Professor Nicholas Harvey, Director of the MRC Centre for Life Course Epidemiology, University of Southampton, UK, IOF President and first author of the paper, said: “This position paper, bringing together international experts from different regions of the world, clarifies the approach to optimising vitamin D status in populations. It was very clear that one size does not fit all and that population and context-specific variables, such as total calcium intake, also need to be considered.

"Approaches may include dietary advice, food fortification, or supplementation, particularly for those at high risk of vitamin D deficiency and associated complications. In contrast, severe vitamin D deficiency associated with signs and symptoms of disease should be evaluated and treated appropriately by a health care professional."