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

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

The work was published in the Osteoporosis International magazine.

Professor Bess Dawson Hughes, Professor of Medicine at Tufts University School of Medicine, Senior Fellow in the Endocrine Division at Tufts Medical Center and senior author of the publication, said: “Vitamin D levels in populations vary across the world and are influenced by a number of factors such as diet, skin pigmentation, clothing, latitude, effective sun exposure and use of supplements.

"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 a public health level, the role of vitamin D supplementation requires different considerations. Here, the goal is to keep vitamin D levels high enough to reduce the risk of overall health problems."

Based on recently published work from the European Society on the clinical and economic aspects of osteoporosis, osteoarthritis and musculoskeletal diseases, the position paper Optimizing Vitamin D Status in Global Populations concludes:

• Maintaining adequate vitamin D levels at the population level is achieved preferably through diet and lifestyle. Food fortification, as practiced in some countries, may provide an alternative route to optimizing vitamin D status. Another approach to meeting vitamin D requirements is supplementation in moderate daily doses. It is important that any intervention takes into account the individual characteristics of the population, including, for example, habitual calcium intake.
• Based on the current evidence base, there is insufficient evidence to support screening for vitamin D deficiency in the general population.
• Screening and/or routine supplementation may be appropriate in high-risk groups, such as older people 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 is likely to be indicated, along with a more aggressive approach to restoring vitamin D levels.
• When a supplement is recommended by a medical professional, it must be in the form of a licensed product to ensure consistency between the prescribed and actual dosage. Because of evidence suggesting 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 out glaring gaps in documentation of vitamin D deficiency worldwide, describing key methodological issues such as assay variability and lack of standardization of reporting. With respect to future research on the epidemiology of vitamin D and to strengthen future guidelines, the authors recommend that standardized measures of 25(OH)D, consistent with the Vitamin D Standardization Program, be reflected in all studies and publications.

Professor Nicholas Harvey, Director of the MRC Center for Life Course Epidemiology at the University of Southampton, UK, President of the IOF and first author of the publication, said: “This position paper, bringing together international experts from different regions of the world, clarifies the approach to optimizing 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 recommendations for diet, food fortification, or supplementation, especially 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 assessed and treated accordingly by a medical professional."