ODIN project examines food-based solutions to prevent vitamin D deficiency

ODIN is a 4 year collaborative project with partners from all over Europe and one from the USA. The coordinator of the project is UCC and other Irish partners include the Daithi O'Murchu Marine Research Station, UCD, Crème Software Ltd (Dublin) and Monaghan Mushrooms.

There are a number of topics under study in ODIN, which include:

• Vitamin D status: distribution of standardized vitamin D concentrations in European populations
• Dietary exposure to vitamin D in European populations
• Sunlight exposure: risk-benefit analysis - implications for vitamin D requirements
• Dietary requirements for vitamin D during pregnancy, childhood and adolescence
• Food- and food-technology-based solutions for prevention of vitamin D deficiency
• Proof of effectiveness of food-based solutions to prevent vitamin D deficiency
• Vitamin D and health outcomes in pregnancy and early life
• Vitamin D and health outcomes in older adults.

The main source of vitamin D is sunlight. However, countries in northern latitudes (greater than 37.5-40º) do not get sufficient sunlight to naturally create vitamin D, particularly in the winter. The period of time when the angle of the sun is too oblique for the UVB rays to pass through ozone, and therefore little or no vitamin D can be dermally synthesized, lasts about 5 months in Ireland. The heightened awareness of the risks of skin cancer also means that people are more likely to keep out of the sun, cover up and wear sunscreen which again limits the body's ability to produce vitamin D. Correct application of SPF15 reduces the skin's natural ability to synthesize vitamin D by 93%. A number of other factors also limit one's ability to obtain enough vitamin D through UVB exposure. These include long working hours spent indoors, the amount of melanin in your skin (i.e. darker-skinned individuals are not able to synthesize as much as a lighter-skinned person exposed to the same level of UVB rays) and age (dermal synthesis of vitamin D is not as efficient in older adults).

A solution to this problem can be found in the diet. There are a number of foods which naturally contain vitamin D and these include oily fish, meat, dairy, egg yolk and mushrooms. Depending on a country's legislation, some foods are also fortified with vitamin D and these include milk, yoghurt, spreads, cheese, juices, bread and cereal. The problem with this is that by fortifying a product such as milk, you are only targeting those who a) drink milk, and b) drink enough of it to make a difference to their vitamin D levels. Studies have shown that intake of vitamin D from fortified foods is very low. Vitamin D is also available as a dietary supplement in tablet form, but of course taking a supplement is voluntary and uptake tends to be low amongst children, adolescents and young adults. Sustainable fortification strategies which incorporate a range of foods have the potential to increase vitamin D intake and reduce deficiency.

DOMMRS' role in this project is to fortify Atlantic salmon with vitamin D. This is important given that the World's wild fish stocks are being overexploited resulting in growth in the aquaculture industry in Europe. It has been found that farmed salmon do not contain as much vitamin D as wild salmon due to differences in their diets. DOMMRS are using 4 different levels of vitamin D over a period of 3 months to determine how inclusion of additional vitamin D in their diet will translate into their flesh. Further studies will examine whether vitamin D from fish is more effective than vitamin D from supplements.

ODIN will also be investigating technological advances for improving the vitamin D content of mushrooms (which, when in powder form can be incorporated into other novel foods), yeast, eggs, beef, pork and fresh-water fish.
Expected outcomes of the project include:

• The primary task of the ODIN project is to create 25OHD (25-hydroxyvitamin D) unified analytical platform and Vitamin D Standardisation Program (VDSP). Meta-analyzes and individual subject-level meta-regression analyzes to integrate standardised data on vitamin D status will be conducted.
• Proposed innovative food-based solutions to increase vitamin D in the food supply chain via the combination of bio-fortification of model foods will be developed on strongevidence bases. Four Randomised Clinical Trials in pregnant women, children, teenagers and ethnic immigrant groups will be carried out. Dietary modelling and novel foods at the same time might be able to meet the expectations of consumers, clinicians and industry.