New position paper addresses optimising vitamin D status in global population

A position paper written on behalf of the International Osteoporosis Foundation (IOF) Vitamin D Working Group summarises the burden of vitamin D deficiency and public health efforts for its prevention in populations worldwide, highlighting key issues such as global variability in vitamin D concentrations and methodological problems regarding testing, guidelines, screening, supplements and food fortification.

The study has been published in the journal Osteoporosis International Society.

“Population-level vitamin D concentrations vary significantly around the world and depend on a variety of factors, including diet, skin pigmentation, skin coverage, latitude, effective sun exposure, and supplement use,” said Professor Beth Dawson Hughes, professor of medicine at Tufts University and senior scientist in the Division of Endocrinology at Tufts Medical Center and lead author of the paper.

“We know that vitamin D is important for overall health, and that in some people severe vitamin D deficiency can lead to serious health problems such as rickets and osteomalacia. These patients require rapid replacement of vitamin D. But at a public health level, the role of vitamin D supplementation presents a different set of considerations. The goal here is to keep vitamin D levels high enough, on average, to reduce the risk of health problems overall.”

Based on a recently published study by the European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases, a position statement called “Optimizing Vitamin D Status in the World Population” concluded:

• Dietary and lifestyle measures are preferred to maintain adequate vitamin D status at the population level. Food fortification, as implemented in some countries, could be another way to optimize vitamin D status. Taking moderate amounts of daily vitamin D supplements is another approach to meet intake requirements. Importantly, interventions need to take into account individual population characteristics, such as habitual calcium intake.
• Based on current evidence, screening for vitamin D deficiency in the general population is insufficient to be justified.
• Screening and regular supplementation may be appropriate in high-risk populations, such as older adults in institutional care and people with pigmented skin living in northern latitudes.
• At the individual patient level, if clinical symptoms suggest vitamin D deficiency, testing may be indicated along with a more aggressive approach to vitamin D supplementation.
• If a health professional recommends taking a supplement, it should be taken in the form of a licensed product to ensure consistency between the prescribed amount and the actual amount. Boluses are generally not recommended unless rapid correction is specifically required, as there is evidence of an increased risk of falls and fractures.

The authors also note clear gaps in the documentation of vitamin D deficiency worldwide and describe major methodological issues, such as testing variability and lack of standardization in reporting. In view of future research on vitamin D epidemiology and future strengthening of guidelines, the authors recommend that standardized measures of 25(OH)D should be reported in all studies and publications according to the Vitamin D Standardization Program.

Professor Nicholas Harvey, Director of the MRC Centre for Lifecourse Epidemiology at the University of Southampton, UK, President of IOF and first author of the paper said: “This position statement, which brings together international experts from different parts of the world, provides clarity on an approach to optimising vitamin D status in populations. It is clear that one size does not fit all and population- and situation-specific variables, such as overall calcium intake, need to be taken into account.”

“Approaches, particularly for those at high risk of vitamin D deficiency and complications, may include guidelines on diet, food fortification and supplementation. Conversely, severe vitamin D deficiency accompanied by signs and symptoms of disease should be appropriately evaluated and treated by a health professional.”