Fortification of Wheat Flour with Vitamins and Minerals as a Public Health Strategy

Overarching principle for recommendations – Fortification of cereal flours, in this case industrially processed/produced wheat flour fortification, should be considered when wheat flour is regularly consumed by large population groups in a country. The fortification scheme in terms of which nutrients to add and in what amounts should be based on the nutritional needs of the population, usual consumption of fortifiable flour, sensory and physical effects of the added nutrients on flour and flour products, type of wheat and the extraction rate of flour, other fortified food items or ongoing micronutrient programmes, and fortification costs, feasibility and acceptance. Based on available evidence, the recommendations to fortify wheat flour are as follows.

The remarks in this section are suggestions intended to give some considerations for implementation of the recommendations, based on the discussions of the guideline development group.

• When vitamin A deficiency constitutes a public health problem and no other/insufficient strategies to address it are in place, fortification of wheat flour with vitamin A could be considered as a public health strategy to improve vitamin A status or to reduce the risk of subclinical vitamin A deficiency.

• In countries with a high prevalence of vitamin B12 depletion and deficiency, the inclusion of vitamin B12 could be considered when staples are fortified with folic acid, to prevent unintended consequences of imbalances caused by the addition of folic acid alone.

• Since some of the B-complex vitamins naturally present in the wheat kernel are removed during milling, especially with low-extraction (i.e. refined) wheat flour, the restoration of thiamine, riboflavin, niacin and pyridoxine in wheat flour could be considered as a regular practice in fortification.

• The choice of iron compound is a compromise between cost, bioavailability, micronutrient interactions and the acceptance of texture, taste, smell and/or colour.

• The removal of phytates in wheat flour could increase the bioavailability of iron and zinc.

• Addition of vitamins and minerals to wheat flour should be based on evidence about inadequacy of micronutrient intakes and/or the prevalence of deficiency. This pre-fortification data will also serve for measuring impact of the fortification programme.

• Countries that fortify wheat flour may also fortify other food items. A combined fortification strategy using multiple vehicles appears to be a suitably effective option for reaching all segments of the population. Fortification of wheat flour should be integrated and monitored as part of their national programmes for prevention and control of micronutrient deficiencies and insufficiencies.

• Food fortification should be guided by national standards, with quality-assurance and qualitycontrol systems to ensure quality fortification. Continuous programme monitoring should be in place as part of a process to ensure high-quality implementation. Monitoring consumption patterns and evaluation of micronutrient status in the population can inform adjustment of fortification levels over time.

• Populations should be encouraged to receive adequate nutrition, which is best achieved through consumption of a healthy balanced diet. Fortified foods only complement the diet when feasible and required.

• Although evidence is limited, fortification of wheat flour could potentially decrease inequity in population access to and consumption of micronutrient required to achieve good health and to prevent adverse health outcomes.

• The following table contains a list of nutrients and levels that could be added to wheat flour for fortification and/or restitution of contents.

The WHO guideline development groups and the systematic reviews teams highlighted the limited evidence available in some areas. Further research on wheat flour fortification is merited, particularly in:

• the bioavailability of different iron compounds for use in wheat flour fortification, including mixtures of different compounds;

• the bioavailability and stability of added folic acid, vitamin A and vitamin D in wheat flour;

• fortification of wheat flour with zinc only in comparison with fortification with a mix of micronutrients;

• the effects of different phytate contents on the absorption of iron and zinc from the premix formulation;

• biomarkers of individual micronutrient status under different conditions of infection and inflammation;

• stability of different micronutrients and compounds in different cooking processes that are context specific;

• relative bioavailability among different chemical forms of various micronutrients that can be used in wheat flour fortification, including nutrient–nutrient interactions;

• the most appropriate delivery platforms of the fortified flour/fortified flour products for reaching the intended target population;

• the impact of wheat flour fortification on micronutrient status and health outcomes to prevent excessive supplies of micronutrients to certain groups and identify situations where complementary interventions are needed to reduce inequity in populations.