One in five British citizens are significantly deficient in vitamin D. Two scientific studies show that enriching flour with vitamin D is the most effective way to combat this deficiency and supply people in Great Britain with the vital “sunshine vitamin.”

A balanced level of vitamin D in the body is essential for health and vitality. Its importance for calcium and bone metabolism has long been known, but recent research shows that this fat-soluble micronutrient has a much broader range of effects on the body than was previously understood. Insufficient vitamin D levels are associated not just with rickets and osteoporosis, but also with diabetes, intestinal cancer, anaemia, high blood pressure and multiple sclerosis.

Poor access to the sunshine vitamin

Like in most countries, people in Great Britain don’t get enough vitamin D. Levels are nowhere near the recommended amount, at 20% in adults and just 16% in youths between 11 and 16.

The problem is that the two major sources of vitamin D — sunlight and certain foods — don’t provide enough of it. The vitamin is present in only a few foods, like fatty fish, organ meat, milk and dairy products, and mushrooms. The body can make its own vitamin D with the help of UVB rays from sunlight on the skin, but the amount produced depends on many factors. Seasons, weather, ethnic group and age all affect the chemical transformation process in the skin. At special risk are seniors, dark-skinned and Asian people, and girls and women who always cover themselves when they go out.

Inadequate measures

To raise vitamin D levels, nutritionists recommend enriching staple foods. However, experience in Great Britain shows that not every such measure has the desired effect. Currently, vitamin D enrichment is mandatory in Great Britain for baby food and margarine, while milk and cereals often are enriched on a voluntary basis as well. And yet the results are modest — the daily intake of vitamin D in the population is often far below the recommended reference value of 400 IU.

Therefore, British experts are calling for a strategic realignment of preventive measures and are looking at foods made with wheat flour. The basis for this is two scientific studies that come to the same conclusion independently of one another, namely that flour enrichment would be the most effective way to significantly raise the vitamin D status of all population groups in the United Kingdom. A great advantage of wheat flour is its versatility. Whether it is bread, baked foods, pizza or pasta, all of these popular foods can carry an extra portion of vitamin D.

Vitamin D boost with flour

An analysis by the London Department of Health in 2015 confirmed that results can be achieved quickly with vitamin-fortified flour. By means of a theoretical test model, it examined how the health of the population would change if milk (up to maximum 7 mg/100 l) and bread (10 μg/100 grams of flour) were enriched. Using existing data, it showed that vitamin D deficiency in the risk groups would be reduced to 50% from 93%. The analysis also showed that flour is more effective than milk. Accordingly, nutritional scientist Dr. Rachel Allen and her team prefer it over dairy products. The study’s conclusion was that “enriching flour with vitamin D would be an advisable option for a sure improvement in the vitamin D intake of the population.”

Scientists at Birmingham University also have shown that fortified flour could significantly raise the amount of vitamin D in the blood serum of people in England and Wales. Empirical calculations indicate that within the next 90 years there will be 40 million new cases of vitamin D insufficiency if the government does not counter this with legislation. In 10 million people (25% of the population), this serious deficit could be prevented quite simply by adding vitamin D to flour. No changes to the diet would be necessary.

Government must react

In a study published in August 2019 in the European Journal of Clinical Nutrition, project director Dr. Magda Aguiar identified the economic benefits of mandatory flour enrichment. Without it, she said, the British National Health Service will see additional costs of £65 million ($80 million) in the time period specified in the study. The costs of mandatory flour enrichment would be negligible by comparison, at just 12 pence per person per year.

Dr. Aguiar urged lawmakers to act.

“There is a strong economic case for fortifying wheat flour with vitamin D,” she said. “We hope that UK policymakers will consider a new national policy to fortify foods such as wheat flour with vitamin D to address this serious health issue. This will lead to significant benefits for the population, particularly the most vulnerable groups.”

Mühlenchemie tests the stability and baking behavior of vitamin D

Mühlenchemie is one of the best-known suppliers of vitamin and mineral premixes, and provides mills with tailor-made raw materials, technical equipment and consulting. In many countries flour enrichment with nutrients like iron, folic acid and zinc is standard, but vitamin D remains on the sidelines. In order to gain more background knowledge on how this micronutrient acts in flour, Mühlenchemie ran a series of application-specific baking and stability tests in the company’s own Stern-Technology Center. The results in brief:

• The tests used spray-dried vitamin D3 (cholecalciferol), with tocopherol to protect it from oxidation. The dosage was 7.5 μg/kg flour, and the test products were bread and biscuits.
• The technologists doing the tests were pleased with the results, in the process and in the baked foods. The powder was easy to work with, distributed very well and affected neither the sensory factors nor the appearance of the final products.

Results with respect to vitamin D stability varied.

In white sandwich bread, an activity loss in the 15% to 20% range was measured. Baking temperature was 200° C. During the 30-minute baking time, the core temperature inside the loaves reached 98° C.

In biscuits, cholecalciferol activity was reduced by about 30%, due to the higher baking temperature and the small, flat shape of the product. The 220° C oven temperature reached the core of the dough during the 10-minute baking time, thus leading to greater activity loss.

Degradation processes of this kind, caused by light, oxygen and heat, are scarcely to be avoided in the food production. However, adjustment of the dosage used in flour enrichment can ensure that the final product has the desired vitamin content even after baking or cooking.

Sven Mattutat is a product manager with Mühlenchemie. He may be contacted at smattutat@muehlenchemie.com.