Vitamin D Intake: A Global Perspective of Current Status

Abstract

Global high prevalence of vitamin D insufficiency and re-emergence of rickets and the growing scientific evidence linking low circulating 25-hydroxyvitamin D to increased risk of osteoporosis, diabetes, cancer, and autoimmune disorders have stimulated recommendations to increase sunlight (UVB) exposure as a source of vitamin D. However, concern over increased risk of melanoma with unprotected UVB exposure has led to the alternative recommendation that sufficient vitamin D should be supplied through dietary sources alone. Here, we examine the adequacy of vitamin D intake worldwide and evaluate the ability of current fortification policies and supplement use practices among various countries to meet this recommendation. It is evident from our review that vitamin D intake is often too low to sustain healthy circulating levels of 25-hydroxyvitamin D in countries without mandatory staple food fortification, such as with milk and margarine. Even in countries that do fortify, vitamin D intakes are low in some groups due to their unique dietary patterns, such as low milk consumption, vegetarian diet, limited use of dietary supplements, or loss of traditional high fish intakes. Our global review indicates that dietary supplement use may contribute 6-47% of the average vitamin D intake in some countries. Recent studies demonstrate safety and efficacy of community-based vitamin D supplementation trials and food staple fortification introduced in countries without fortification policies. Reliance on the world food supply as an alternative to UVB exposure will necessitate greater availability of fortified food staples, dietary supplement use, and/or change in dietary patterns to consume more fish.

Vitamin D deficiency in early childhood: prevalent in the sunny South Pacific

“…Based on literature from other countries that do not have mandatory fortification, intake is likely to be well below the currently recommended intake of 200 IU/d (57) . Mandatory fortification of food with vitamin D would be expected to increase vitamin D intake (64) . However, in countries where this is already policy, it is not sufficient to prevent vitamin D deficiency in higher-risk groups (64) .…”

25-Hydroxyvitamin D, IGF-1, and Metabolic Syndrome at 45 Years of Age

“…Hypovitaminosis D is a worldwide problem (26,27), as is the increasing prevalence of metabolic syndrome, type 2 diabetes, and cardiovascular disease (28). We have, therefore, examined the associations of both vitamin D status (serum 25(OH)D) and circulating IGF-1 with metabolic syndrome and its individual components in nearly 7,000 participants in the 1958 British birth cohort at age 45 years (29).…”

Low 25(OH) vitamin D concentrations in international UK track and field athletes

“…Recent population studies have illustrated a significant prevalence of vitamin D deficiency in the general population, [14][15][16][17] and athletes also seem to be susceptible. [18][19][20] Serum 25(OH)D is widely accepted as a biomarker for vitamin D status.…”