Vitamin D deficiency as a public health issue: using vitamin D2 or vitamin D3 in future fortification strategies

Rationale and design of a placebo controlled randomized trial to assess short term, high-dose oral cholecalciferol on select laboratory and genomic responses in African Americans with hypovitaminosis D

Cardiovascular Disease (CVD) and related disorders remain a leading cause of health disparities and premature death for African Americans. Hypovitaminosis D is disproportionately prevalent in African Americans and has been linked to CVD and CVD risk factors including hypertension, diabetes and obesity. Thus, hypovitaminosis D may represent a common pathway influencing CV risk factors in a select subgroup of persons. The purpose of this paper is to report the study design of a prospective eight week prospective double-blind randomized, placebo-controlled trial (n = 330 allocated 2:1 to intervention vs. control) to assess the effect of placebo vs. high-dose oral cholecalciferol (100,000 IU vitamin D3 at baseline and week 2) on 6-week change of select biologic cardiometabolic risk factors (including parathyroid hormone to assess biologic activity, pro-inflammatory/pro-thrombotic/fibrotic markers, insulin sensitivity and vitamin D metabolites) and their relationship to vitamin D administration and modification by vitamin D receptor polymorphisms in overweight, hypertensive African Americans with hypovitaminosis D. Findings from this trial will present insights into potential causal links between vitamin D repletion and mechanistic pathways of CV disease, including established and novel genomic markers.

Vitamin D fortification of foods and prospective health outcomes

Vitamin D is essential for bone health and has significant roles in non-skeletal health and organ function. Dermal synthesis through exposure to ultraviolet B light is the major natural source of vitamin D, while only a small portion of the necessary amount can be acquired by a diet without fortified foods. In recent years, vitamin D deficiency as a result of lifestyles with inadequate sun exposure, has received increased attention due to its association with the increased risk of serious chronic diseases. This review summarizes our current understanding of food fortification strategies with vitamin D and the resulting health impact. Conventional and biotechnological approaches can be used for the production of new and novel vitamin D rich or vitamin D fortified foods. The availability of a wider range of every-day consumed fortified foods as part of a "Daily D" public health policy can contribute to the improvement of vitamin D status and to prevention of vitamin D deficiency.

Vitamin D-biofortified beef: A comparison of cholecalciferol with synthetic versus UVB-mushroom-derived ergosterol as feed source

This study investigates dietary fortification of heifer feeds with cholecalciferol and ergocalciferol sources and effects on beef total vitamin D activity, vitamer, respective 25-hydroxymetabolite contents, and meat quality. Thirty heifers were allocated to one of three dietary treatments [(1) basal diet + 4000 IU of vitamin D₃ (Vit D₃); (2) basal diet + 4000 IU of vitamin D₂ (Vit D₂); and (3) basal diet + 4000 IU of vitamin D₂-enriched mushrooms (Mushroom D₂)] for a 30 day pre-slaughter period. Supplementation of heifer diets with Vit D₃ yielded higher (p < 0.001) Longissimus thoracis (LT) total vitamin D activity (by 38-56%; p < 0.05) and serum 25-OH-D concentration (by 20-36%; p < 0.05), compared to that from Vit D₂ and Mushroom D₂ supplemented animals. Irrespective of vitamin D source, carcass characteristics, sensory and meat quality parameter were unaffected (p > 0.05) by the dietary treatments. In conclusion, vitamin D₃ biofortification of cattle diets is the most efficacious way to enhance total beef vitamin D activity.

Rationale and Plan for Vitamin D Food Fortification: A Review and Guidance Paper

Vitamin D deficiency can lead to musculoskeletal diseases such as rickets and osteomalacia, but vitamin D supplementation may also prevent extraskeletal diseases such as respiratory tract infections, asthma exacerbations, pregnancy complications and premature deaths. Vitamin D has a unique metabolism as it is mainly obtained through synthesis in the skin under the influence of sunlight (i.e., ultraviolet-B radiation) whereas intake by nutrition traditionally plays a relatively minor role. Dietary guidelines for vitamin D are based on a consensus that serum 25-hydroxyvitamin D (25[OH]D) concentrations are used to assess vitamin D status, with the recommended target concentrations ranging from ≥25 to ≥50 nmol/L (≥10-≥20 ng/mL), corresponding to a daily vitamin D intake of 10 to 20 μg (400-800 international units). Most populations fail to meet these recommended dietary vitamin D requirements. In Europe, 25(OH)D concentrations <30 nmol/L (12 ng/mL) and <50 nmol/L (20 ng/mL) are present in 13.0 and 40.4% of the general population, respectively. This substantial gap between officially recommended dietary reference intakes for vitamin D and the high prevalence of vitamin D deficiency in the general population requires action from health authorities. Promotion of a healthier lifestyle with more outdoor activities and optimal nutrition are definitely warranted but will not erase vitamin D deficiency and must, in the case of sunlight exposure, be well balanced with regard to potential adverse effects such as skin cancer. Intake of vitamin D supplements is limited by relatively poor adherence (in particular in individuals with low-socioeconomic status) and potential for overdosing. Systematic vitamin D food fortification is, however, an effective approach to improve vitamin D status in the general population, and this has already been introduced by countries such as the US, Canada, India, and Finland. Recent advances in our knowledge on the safety of vitamin D treatment, the dose-response relationship of vitamin D intake and 25(OH)D levels, as well as data on the effectiveness of vitamin D fortification in countries such as Finland provide a solid basis to introduce and modify vitamin D food fortification in order to improve public health with this likewise cost-effective approach.