Fortification of Foods with Vitamin D in India

Vitamin D deficiency is widely prevalent in India, despite abundant sunshine. Fortification of staple foods with vitamin D is a viable strategy to target an entire population. Vitamin D fortification programs implemented in the United States and Canada have improved the vitamin D status in these countries, but a significant proportion of the population is still vitamin D deficient. Before fortification programs are designed and implemented in India, it is necessary to study the efficacy of the American and Canadian vitamin D fortification programs and then improve upon them to suit the Indian scenario. This review explores potential strategies that could be used for the fortification of foods in the Indian context. These strategies have been proposed considering the diverse dietary practices necessitated by social, economic, cultural and religious practices and the diverse climatic conditions in India. Fortification of staple foods, such as chapati flour, maida, rice flour and rice, may be more viable strategies. Targeted fortification strategies to meet the special nutritional needs of children in India are discussed separately in a review entitled, “Fortification of foods with vitamin D in India: Strategies targeted at children”.     

Influences of Vitamin D and Iron Status on Skeletal Muscle Health: A Narrative Review

There is conflicting evidence of the roles vitamin D and iron have in isolation and combined in relation to muscle health. The purpose of this narrative review was to examine the current literature on the roles that vitamin D and iron have on skeletal muscle mass, strength, and function and how these nutrients are associated with skeletal muscle health in specific populations. Secondary purposes include exploring if low vitamin D and iron status are interrelated with skeletal muscle health and chronic inflammation and reviewing the influence of animal-source foods rich in these nutrients on health and performance. PubMed, Scopus, SPORT Discus, EMBAE, MEDLINE, and Google Scholar databases were searched to determine eligible studies. There was a positive effect of vitamin D on muscle mass, particularly in older adults. There was a positive effect of iron on aerobic and anaerobic performance. Studies reported mixed results for both vitamin D and iron on muscle strength and function. While vitamin D and iron deficiency commonly occur in combination, few studies examined effects on skeletal muscle health and inflammation. Isolated nutrients such as iron and vitamin D may have positive outcomes; however, nutrients within food sources may be most effective in improving skeletal muscle health.     

Does the High Prevalence of Vitamin D Deficiency in African Americans Contribute to Health Disparities?

African Americans have higher incidence of, and mortality from, many health-related problems than European Americans. They also have a 15 to 20-fold higher prevalence of severe vitamin D deficiency. Here we summarize evidence that: (i) this health disparity is partly due to insufficient vitamin D production, caused by melanin in the skin blocking the UVB solar radiation necessary for its synthesis; (ii) the vitamin D insufficiency is exacerbated at high latitudes because of the combination of dark skin color with lower UVB radiation levels; and (iii) the health of individuals with dark skin can be markedly improved by correcting deficiency and achieving an optimal vitamin D status, as could be obtained by supplementation and/or fortification. Moderate-to-strong evidence exists that high 25-hydroxyvitamin D levels and/or vitamin D supplementation reduces risk for many adverse health outcomes including all-cause mortality rate, adverse pregnancy and birth outcomes, cancer, diabetes mellitus, Alzheimer’s disease and dementia, multiple sclerosis, acute respiratory tract infections, COVID-19, asthma exacerbations, rickets, and osteomalacia. We suggest that people with low vitamin D status, which would include most people with dark skin living at high latitudes, along with their health care provider, consider taking vitamin D₃ supplements to raise serum 25-hydroxyvitamin D levels to 30 ng/mL (75 nmol/L) or possibly higher.     

Vitamin D: An overview of vitamin D status and intake in Europe

In recent years, there have been reports suggesting a high prevalence of low vitamin D intakes and vitamin D deficiency or inadequate vitamin D status in Europe. Coupled with growing concern about the health risks associated with low vitamin D status, this has resulted in increased interest in the topic of vitamin D from healthcare professionals, the media and the public. Adequate vitamin D status has a key role in skeletal health. Prevention of the well‐described vitamin D deficiency disorders of rickets and osteomalacia are clearly important, but there may also be an implication of low vitamin D status in bone loss, muscle weakness and falls and fragility fractures in older people, and these are highly significant public health issues in terms of morbidity, quality of life and costs to health services in Europe. Although there is no agreement on optimal plasma levels of vitamin D, it is apparent that blood 25‐hydroxyvitamin D [25(OH)D] levels are often below recommended ranges for the general population and are particularly low in some subgroups of the population, such as those in institutions or who are housebound and non‐Western immigrants. Reported estimates of vitamin D status within different European countries show large variation. However, comparison of studies across Europe is limited by their use of different methodologies. The prevalence of vitamin D deficiency [often defined as plasma 25(OH)D <25 nmol/l] may be more common in populations with a higher proportion of at‐risk groups, and/or that have low consumption of foods rich in vitamin D (naturally rich or fortified) and low use of vitamin D supplements. The definition of an adequate or optimal vitamin D status is key in determining recommendations for a vitamin D intake that will enable satisfactory status to be maintained all year round, including the winter months. In most European countries, there seems to be a shortfall in achieving current vitamin D recommendations. An exception is Finland, where dietary survey data indicate that recent national policies that include fortification and supplementation, coupled with a high habitual intake of oil‐rich fish, have resulted in an increase in vitamin D intakes, but this may not be a suitable strategy for all European populations. The ongoing standardisation of measurements in vitamin D research will facilitate a stronger evidence base on which policies can be determined. These policies may include promotion of dietary recommendations, food fortification, vitamin D supplementation and judicious sun exposure, but should take into account national, cultural and dietary habits. For European nations with supplementation policies, it is important that relevant parties ensure satisfactory uptake of these particularly in the most vulnerable groups of the population.     

Impact of national fortification of fluid milks and margarines with vitamin D on dietary intake and serum 25-hydroxyvitamin D concentration in 4-year-old children

OBJECTIVE: To assess the impact of national fortification of fluid milks and margarines with vitamin D on dietary intake and on serum 25-hydroxyvitamin D concentration in Finnish 4-year-old children. DESIGN, SUBJECTS AND METHODS: Two cohorts of children were studied during wintertime, one before (n=82) in 2001-2002 and the other after (n=36) the initiation of fortification in 2003-2004. Dietary intake was estimated by 4-day food records and serum 25-hydroxyvitamin D concentration was analyzed by radioimmunoassay. RESULTS: The mean intake of vitamin D was higher the after initiation of fortification (mean (95% confidence interval (CI)); 4.5 (3.8-5.1) microg) than before it (2.1 (95% CI 1.8-2.3) microg; P<0.001), although there were no differences in consumption of the main food sources of vitamin D between the two cohorts. The difference between the cohorts was also evident when the intake of vitamin D was adjusted for energy intake (0.78 (95% CI 0.70-0.90) and 0.37 (95% CI 0.32-0.42) microg/MJ after and before fortification, respectively, P<0.001). After fortification, the mean intake approached that recommended, but was achieved by only 30.6% of the children. Equally, the serum 25-hydroxyvitamin D concentration was higher after fortification (64.9 (95% CI 59.7-70.1) nmol/l) compared to prior it (54.7 (95% CI 51.0-58.4) nmol/l; P=0.002). CONCLUSIONS: The results indicate that the national fortification of fluid milks and margarines with vitamin D safely improved the vitamin D status of children. This approach, in view of the novel health effects beyond bone metabolism, encourages fortification of new food sources with vitamin D or use of vitamin D supplements particularly during wintertime.     

The Key Role of Government in Addressing the Pandemic of Micronutrient Deficiency Conditions in Southeast Asia

Micronutrient deficiency conditions are a major global public health problem. While the private sector has an important role in addressing this problem, the main responsibility lies with national governments, in cooperation with international agencies and donors. Mandatory fortification of basic foods provides a basic necessary intake for the majority and needs to be supported by provision of essential vitamin and mineral supplements for mothers and children and other high risk groups. Fortification by government mandate and regulation is essential with cooperation by private sector food manufacturers, and in the context of broader policies for poverty reduction, education and agricultural reform. Iron, iodine, vitamin A, vitamin B complex, folic acid, zinc, vitamin D and vitamin B12 are prime examples of international fortification experience achieved by proactive governmental nutrition policies. These are vital to achieve the Millennium Development Goals and their follow-up sustainable global health targets. National governmental policies for nutritional security and initiatives are essential to implement both food fortification and targeted supplementation policies to reduce the huge burden of micronutrient deficiency conditions in Southeast Asia and other parts of the world.     

Potential of Vitamin D Food Fortification in Prevention of Cancer Deaths—A Modeling Study

Meta-analyses of randomized controlled trials (RCTs) have estimated a 13% reduction of cancer mortality by vitamin D supplementation among older adults. We evaluated if and to what extent similar effects might be expected from vitamin D fortification of foods. We reviewed the literature on RCTs assessing the impact of vitamin D supplementation on cancer mortality, on increases of vitamin D levels by either supplementation or food fortification, and on costs of supplementation or fortification. Then, we derived expected effects on total cancer mortality and related costs and savings from potential implementation of vitamin D food fortification in Germany and compared the results to those for supplementation. In RCTs with vitamin D supplementation in average doses of 820–2000 IU per day, serum concentrations of 25-hydroxy-vitamin D increased by 15–30 nmol/L, respectively. Studies on food fortification found increases by 10–42 nmol/L, thus largely in the range of increases previously demonstrated by supplementation. Fortification is estimated to be considerably less expensive than supplementation. It might be similarly effective as supplementation in reducing cancer mortality and might even achieve such reduction at substantially larger net savings. Although vitamin D overdoses are unlikely in food fortification programs, implementation should be accompanied by a study monitoring the frequency of potentially occurring adverse effects by overdoses, such as hypercalcemia. Future studies on effectiveness of vitamin D supplementation and fortification are warranted.     

Vitamin D fortification as public health policy: significant improvement in vitamin D status in young Finnish men

BACKGROUND: Vitamin D insufficiency is common in northern countries during wintertime. In Finland, after the recommendation by the Ministry of Social Affairs and Health, vitamin D has been added to liquid milk products and margarines from February 2003. OBJECTIVE: We determined the effects of national policy on vitamin D fortification on vitamin D status among young Finnish men. DESIGN: A comparison before and after intervention with study population of 196 young Finnish men (18-28 years) was carried out. Serum 25-hydroxyvitamin D3 (25-OHD3) concentrations were determined with the OCTEIA enzymeimmunoassay by IDS (Immunodiagnostic Systems Limited, Bolden, UK) in January 2003 (n = 96) and in January 2004 (n = 100), nearly 1 year after national vitamin D fortification had started. RESULTS: The mean serum 25-OHD3 concentrations during the wintertime increased by 50% after implementation of the vitamin D fortification of dairy products. Correspondingly, the prevalence of vitamin D insufficiency (serum 25-OHD3 < 40 nmol/l) was decreased by 50% from 78% in January 2003 to 35% in January 2004. CONCLUSIONS: Our results demonstrate that national vitamin D fortification substantially improved the vitamin D status of young Finnish men. Still, a third remained vitamin D insufficient.     

Vitamin D: important from before the cradle and to the grave

Approximately one hundred years ago, vitamin D was recognized as being important for bone health. Nowadays there is increasing evidence that even before birth as well as during lifetime, vitamin D plays a role in the prevention of several chronic diseases as well as cancer. Human beings depend on exposure to the sun to satisfy their daily requirements of vitamin D. Moreover, most doctors in the Netherlands are unaware that the production of vitamin D only takes place in the spring and summertime in the Dutch climate. One Dutch study reports hypovitaminosis D not only in more than half of non-western immigrant mothers and their newborns, but also in 10% of the western mothers and their babies. On a worldwide level, numerous studies report low vitamin-D status in western countries due to our modern way of living, the immigration of dark-skinned people to higher latitudes and the homebound elderly. For some years now the scientific world has called for action on this point; something that in practice appears to be difficult to achieve. Aiming for optimal vitamin-D levels means suppletion either through tablets or food fortification. In general, people do not like to take tablets ('we eat healthy foods already') and many avoid the sun because they are afraid of cancer. Vitamin D is not a commercially rewarding product and has no marketing industry. Although multivitamins are marketed and pushed by industry, they hardly contain the necessary amounts of vitamin D. The population in the Netherlands should be better informed on this issue and general practitioners need more tools in order to play a greater role in informing and advising their patients.     

Nutritional Supplements for Older Adults: Review and Recommendations—Part I

The majority of older adults take nutritional supplements (NS) to prevent deficiencies and/or because they are interested in the potential health promoting effects of these nutrients. This review explores the evidence of benefit for supplements of multivitamin/minerals (MVM), antioxidant nutrients, and vitamin D/calcium. Major conclusions include the following: While recommendations that older adults take a daily MVM are common, there is limited scientific support for the health-related efficacy of these supplements. In contrast, a number of antioxidant nutrients have been extensively studied. The evidence does not support a recommendation for vitamins A, C, E, or antioxidant combinations in the prevention of CVD or cancer. Based on encouraging preliminary findings, more study is recommended on the benefit of antioxidant supplements for age-related macular degeneration and of selenium for cancer prevention. In contrast to the state of the art for antioxidant supplements, there is strong and compelling support for the health benefits of supplements of Vitamin D and calcium when intake/status of these nutrients is not optimal. Thus, specific recommendations for these supplements in older adults are warranted.     

Food fortification and biofortification as potential strategies for prevention of vitamin D deficiency

Hypovitaminosis D (vitamin D deficiency) is widespread throughout the world. The cutaneous production of vitamin D through sunlight can be limited by several factors (e.g. skin pigmentation, sunscreen usage and, increasingly, indoor lifestyle). Thus, diet has become an important strategy to increase vitamin D intake and status {blood 25‐hydroxyvitamin D [25(OH)D]}. However, there are a limited number of foods that naturally contain vitamin D, and concentrations can vary significantly between and within species. The need for vitamin D‐fortified foods (including via direct fortification and biofortification) to support the adequacy of vitamin D status is a corollary of several limitations to synthesise vitamin D from sunlight. Ergocalciferol (vitamin D₂) and cholecalciferol (vitamin D₃) can be found in some mushrooms and animal‐derived foods, respectively. Evidence has shown vitamin D₃ is more effective than vitamin D₂ at raising 25(OH)D blood concentrations. The vitamin D metabolite, 25(OH)D_3, is present in animal‐derived foods (e.g. meat, eggs and fish), and several intervention trials have shown 25(OH)D₃ to be more effective at raising blood 25(OH)D concentrations than vitamin D₃. In addition, 25(OH)D₃ supplements may prove to be preferable to vitamin D₃ for patients with certain clinical conditions. However, there is limited evidence on the effects of 25(OH)D₃‐fortified foods on human vitamin D status and health, both in the general population and patients with certain conditions, and long‐term randomised controlled trials are needed in this area.     

Vitamin D intake: a global perspective of current status

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.     

A place for palm fruit oil to eliminate vitamin A deficiency

There is general consensus that food-based approaches are viable and sustainable options for addressing vitamin A deficiency in populations. One such example is the fortification of food which, if properly monitored, could make a significant contribution towards improving the vitamin A status of populations throughout the world. Red palm fruit oil (RPO) with its high content of natural carotenoids, lends itself exceptionally well to this purpose at both household and commercial level. Results are now available from several feeding trials incorporating RPO into diets at household level or into commercially manufactured products. RPO in the maternal diet was shown to improve the vitamin A status of lactating mothers and their infants. Consumption of RPO incorporated in a sweet snack or biscuits significantly improved plasma retinol concentrations in children with subclinical vitamin A deficiency. There is evidence that if only 35-50% of the recommended daily intake for vitamin A were to be provided by RPO, it may be sufficient to prevent vitamin A deficiency (hypovitaminosis A). Red palm oil has a highly bioconvertible form of alpha- and beta-carotene, a long shelf life, and a higher cost/benefit ratio when compared to other approaches such as high-dose-vitamin A supplements and fortification of foods with retinyl ester fortificants. Consumption of RPO is safe and cannot produce hypervitaminosis A. Considering all the current information about RPO, the initiation of food-based interventions involving its use in developing countries with an endemic vitamin A deficiency problem, appears to be a logical choice.     

The Vitamin D and Cancer Conundrum: Aiming at a Moving Target

The case for the influence of vitamin D on health, including cancer prevention, is increasingly compelling. While some are calling for increases in the Tolerable Upper Intake Level, fortification, and dietary supplementation, questions regarding dose and individual response variability continue to merit attention. Colorectal cancer risk reduction with adequate vitamin D status is well documented. Protection has also been observed for cancer at all sites, skin, prostate, and breast. At the same time, some individuals may be adversely affected by elevated 25(OH)D concentrations with respect to risk of cancers of the prostate, breast, pancreas, and esophagus, and in some cases a U- or J-shaped association has been suggested. Future research should seek to clarify if and for whom there may be an increased risk for cancer at particular sites with high 25(OH)D concentrations, and the concentrations at which risk increases. Fundamentally, prospective longitudinal studies of these relationships are warranted. The health status, life stage, adiposity, estrogen exposure, and nutritional status of study participants should be taken into account. Continued investigation is necessary to ensure that vitamin D recommendations are appropriately targeted to individuals who stand to benefit most, while protecting vulnerable subgroups from risk of overexposure.     

Geographical differences in vitamin D status, with particular reference to European countries

Vitamin D is produced endogenously when the skin is exposed to sunlight and can be obtained exogenously from a few natural food sources, from food fortification and from supplements. Generally, vitamin D intake is low < or = 2-3 microg/d in Europe. Casual exposure to sunlight is thought to provide most of the vitamin D requirement of the human population. However, skin synthesis of vitamin D may not compensate for the low nutritional intake in Europe, even in countries with high supplies from food fortification and supplements. For assessment of vitamin D nutritional status the concentration of 25-hydroxyvitamin D (25(OH)D) in serum is considered to be an accurate integrative measure reflecting an individual's dietary intake and cutaneous production. A substantial percentage of the elderly and adolescents in Europe have a low concentration of 25(OH)D; in the elderly this percentage ranges from approximately 10 in the Nordic countries to approximately 40 in France. Low vitamin D status seems to be aggravated by disease and immobility, and by a low frequency of supplement use.     

Public health strategies to overcome barriers to optimal vitamin D status in populations with special needs

In North America, there is increasing public health awareness of the importance of adequate vitamin D intake to the maintenance of optimal vitamin D status and overall health. Experts now define this as circulating levels of 25-hydroxyvitamin D of 75-80 nmol/L. This serum level and high levels of dietary intake have been associated with significantly reduced risk of chronic diseases, such as osteoporosis, cardiovascular disease, diabetes, and some cancers. All of these diseases are more prevalent in the elderly of all races, and some are more prevalent and of greater severity among blacks than whites. Our objective is to review recent actions to increase public awareness of the health importance of maintaining optimal circulating 25(OH)D and potential strategies to increase vitamin D intake. Clinicians and educators are encouraged to promote improved vitamin D intake and status, particularly among the elderly and blacks. This will largely depend on combined efforts to judiciously fortify our food supply and to develop individual supplementation protocols for supplements or controlled use of UV light exposure to maintain optimal serum 25(OH)D, especially in high-risk groups. Growing evidence supports a low risk of toxicity with vitamin D use in fortification or supplementation, despite its past reputation of potential toxicity in excess. The cost to fortify food or supplements with vitamin D is relatively inexpensive compared with developing drugs used to treat or prevent chronic diseases; moreover, there is significant potential for broad health benefits in the reduced risk and prevention of multiple chronic diseases.     

Vitamin D intake in Australian adults and the modeled effects of milk and breakfast cereal fortification

ObjectiveVitamin D intake from foods or supplements is a safe and attractive means to improve vitamin D status of populations. The aim of this study was to help identify population subgroups that would benefit most from efforts to increase intake. To do so, we investigated which personal characteristics are associated with vitamin D intake in an Australian population and modeled possible effects of expanded food fortification practices.MethodsWe investigated vitamin D intake in a population-based random sample of 785 adults, using a validated food frequency questionnaire, and assessed associations with personal and behavioral characteristics. We identified vitamin D food sources and modeled the hypothetical effects of blanket fortification of milk and breakfast cereals.ResultsAverage total vitamin D intake was 4.4 (±4.0) μg/g and below adequate intake for most participants in all age and sex subgroups. Higher intake was associated with being female, having a serious medical condition, energy intake below the median, and vitamin D supplement use (all P < 0.05). The “meat, fish, and eggs” food group contributed most to total vitamin D intake (51%), followed by dairy products and related foods (43%). If all milk and breakfast cereals were to be fortified with vitamin D, the average intake of vitamin D from foods would increase from 3.6 (±2.4) μg/d to 6.3 (±3.2) μg/d, with similar increases in all age and sex subgroups.ConclusionsVitamin D intake in Australia is generally below recommended levels, and few personal characteristics help to identify subgroups with low intake. Blanket vitamin D fortification of milk and breakfast cereals would substantially increase average vitamin D intake in Australian adults of all ages.     

Update on vitamin D and type 2 diabetes

The prevalence of type 2 diabetes mellitus continues to climb in many parts of the globe in association with the rise in obesity. Although the latter is clearly a predominant factor in the pathogenesis of type 2 diabetes, other modifiable lifestyle factors such as exercise, alcohol consumption, smoking, and certain nutritional factors, such as vitamin D deficiency, are also believed to play a role. In contrast to the findings of observational studies, information pooled from vitamin D intervention trials lack conclusive evidence in support of vitamin D supplementation and changes in diabetes risk or measures of glucose intolerance, although an effect on insulin resistance may exist. Well-designed trials that focus on intermediate biomarkers of diabetes risk in response to increased vitamin D intake are still needed. It will be important to include in the design of these studies selection of insulin-resistant study subjects who have a low (< 50 nmol/L) initial serum vitamin D (25-hydroxyvitamin D) status and administration of sufficient vitamin D to adequately increase their vitamin D status to > 75 nmol/L serum 25-hydroxyvitamin D.