The proportion of elderly people in Europe is currently around 20% and this is predicted to increase to 25% by 2020. The most dramatic demographic changes are in the oldest age group (80 years and over). A number of factors, including nutrition, have contributed to this increase in life expectancy. This global phenomenon has spiked renewed interest in the ageing process amongst researchers, policy makers and industry alike.

At a November, 2004 European Commission Workshop, scientists shared progress reports on research related to nutrition and ageing in order to draw lessons for health care and identify priorities for the future. Nutrition and ageing was a priority in the European Union’s Fifth Framework Programme that funded ten research projects on this area. Among them, some of the topics addressed were: diet and prevention of Alzheimer’s diseases (LIPIDIET); functional foods for the older population (CROWNALIFE) or vitamin D and bone health (OPTIFORD). The focus of this article is on Vitamin D and bone health and the goal of the OPTIFORD Project.

Nutrition challenges

The sheer fact that the population is living longer is fueling the prevalence of osteoporosis. Osteoporosis is a disease characterized by low bone mass and deterioration of bone tissue. This leads to increased bone fragility and risk of fracture, particularly of the hip, spine and wrist.
Among an ageing population, several factors contribute to the risk of osteoporosis including poor-quality diets, an inability to fully adapt to low calcium intakes, low physical activity and exposure to sunlight, and low levels or a lack of female and male sex hormones. Although osteoporosis is less common in men than in women, men can be at high risk for this disease. A consequence of this is that men are often unaware of the preventative measures they can take to protect themselves against the disease.
While inadequate calcium in the diet is a known dietary factor in the development of osteoporosis, chronic Vitamin D deficiency also plays a role. With an insufficient supply of Vitamin D the body’s capacity to utilize calcium is compromised – thereby contributing to the development of osteoporosis.

Vitamin D and bone health

Vitamin D is a fat-soluble vitamin essential for maintaining bone health. It facilitates the efficient utilization of calcium by the body. Calcium, in turn, is essential for normal functioning of the nervous system, for bone growth and maintenance of bone density.

Vitamin D can be obtained through sunlight and foods. Exposure to sunlight, (ultra violet B photons (UVB)), is the primary source. However, there are factors that limit utilization of UVB to synthesize Vitamin D in the skin, including season, location, time of day, smog, and age. For example, people living in the northern or southern hemispheres (latitudes 40 degrees north or south) are not exposed to enough UVB during the winter months to allow formation of Vitamin D. With age the body’s capacity to synthesize Vitamin D through exposure to the sun decreases significantly.

Vitamin D is found in a few foods naturally – the best sources are fatty fish like salmon, mackerel and sardines. Vitamin D is also found in a limited number of fortified foods. In Europe, some countries fortify margarine and some cereals products.

The OPTIFORD project

The goal of the OPTIFORD research team, comprised of researchers from 5 European countries, is to improve vitamin D status of large population groups, such as the elderly, in Europe. Their objective is to reduce osteoporosis through a better supply of dietary vitamin D.

The project is investigating whether bread fortification with vitamin D is a feasible strategy to remedy insufficient vitamin D status of large population groups (e.g. the elderly) in Europe, and to determine at what level fortification should be pitched. An important outcome is to reinforce the scientific base for recommendations on vitamin D as a nutrient. The preliminary results show that this could be feasible.

References

• Optiford Project www.optiford.org
• European Research
• World Health Organization: Active Ageing: A Policy Framework Report of the Noncommunicable Disease Prevention and Health Promotion Department: Ageing and Life Course: www.who.int/hpr/ageing
• Holick, M.F. Sunlight and vitamin D for bone health and prevention of autoimmune diseases, cancers and cardiovascular disease. Am J Clin Nutr 2004; 80 (suppl): 1678S-1688S.
• New, S.A. Exercise, bone and nutrition Proceedings of the Nutrition Society (2001), 60, 265 – 274.

FOOD TODAY 04/2005