Vitamin D is synthesised in the body on exposure to sunlight and only small amounts can be obtained from food. As much as 60 per cent of the UK population - exposed to little sunlight during the winter months - is estimated to be vitamin D deficient.
Yet although recent studies have linked deficiency of the vitamin to higher risk of serious disease, cancer campaigners continue to warn consumers about the dangers of exposing skin to sunlight for long periods. This has prompted scientists to urge greater intake of the vitamin from the diet.
Sue Fairweather-Tait, head of nutrition at the UK's Institute of Food Research, told NutraIngredients.com in 2004: "Fortification, if done sensibly, is the only way to achieve optimum vitamin D levels. The best source of vitamin D at the moment is fortified cereals."
It appears that food makers are already increasing the number of products with added vitamin D available to consumers interested in boosting their uptake.
Mintel's Global New Product Database showed 186 launches worldwide in 2003 for foods described as vitamin/mineral fortified and containing vitamin D as a key ingredient. Worldwide product launches rose to 286 in 2005.
The US accounted for 180 of these over the period 2003 to 2005, while the EU-15 saw 134 products launched in the same period. The majority of the new products were breakfast cereals, milk or baby foods.
New research out of the US last week looks set to further boost the demand for vitamin D fortification. Researchers reported that intakes of 1000 IU of the vitamin - significantly higher than most people's typical intake - could reduce the risk of certain cancers by as much as 50 per cent.
The research triggered a flood of new demand for supplements in the UK. Britain's largest supermarket chain, Tesco, said it had witnessed a 400 per cent increase in the sales of vitamin D supplements since the end of December.
Health and beauty retailer Superdrug said that it had seen a 100 per cent increase in sales of supplements containing vitamin D in the two days following the media's reports about the new study.
Most of the studies done on vitamin D's link to cancer risk are epidemiological and therefore cannot confirm a direct cause and effect relationship with lower risk of the disease.
However there is significant evidence to show that vitamin D plays a major role in bone health and could therefore be key to preventing osteoporosis, one of the world's growing publich health problems that remains uncurable.
Both Denmark and the UK have recently launched public health campaigns to encourage consumers to increase vitamin D levels in their diet or through supplements.
But although much of the vitamin D fortification foods has so far been designed to improve bone health, work on mechanisms for cancer risk reduction is ongoing and is likely to further increase demand for this vitamin.
The vitamin's protection is proposed to be multifaceted, by reducing the formation of blood vessels in tumours (angiogenesis), stimulating the mutual adherence of cells, and enhancing intercellular communication through gap junctions. All this adds up to stop proliferation of cancerous cells by contact inhibition.