Micronutrient deficiency, sometimes referred to as “hidden hunger,” is often less visible than other forms of malnutrition but is nonetheless a major cause of serious health problems. In Senegal, micronutrient deficiencies are recognized as a significant public health problem despite limited data on their magnitude and geographic distribution in the country. Senegal’s 2017-2021 Multisectoral Strategic Nutrition Plan (PSMN) (Government of Senegal, 2017) argues that micronutrient deficiencies constitute a major challenge in Senegal’s nutrition landscape [1] .

In 2017, global hunger increased for the first time in a decade, reaching 815 million hungry people2, an increase of 38 millions compared to 2016. While 155 million children under 5 years of age are stunted, caused by poor nutrition, levels of micronutrient deficiencies are alarming: 2 billion people suffer from micronutrient deficiencies, also known as “hidden hunger3”. National and international health organizations are increasingly emphasizing micronutrient fortification programs as a promising way to address deficiencies in low- and middle-income countries [2] .

Vitamin and mineral deficiencies, or “hidden hunger,” are a real public health problem worldwide, particularly in sub-Saharan Africa, where a third of the population continues to suffer from them.

In Senegal, the proportion of children under six years of age affected by subclinical vitamin A deficiency is 61%, while anemia, which is most often the result of dietary iron deficiency, affects 82.6% of children aged 6 to 59 months and 59.1% of women aged 15 to 49 (2005 Senegal Demographic and Health Survey) [3] .

The health and socioeconomic consequences of these nutritional deficiencies are considerable: increased mortality and morbidity, impaired physical and mental development, and reduced work and learning capacities. Food fortification is undeniably recognized as one of the most cost-effective interventions worldwide.

According to the FAO and WHO guiding principles, food fortification is defined as “the action of deliberately increasing the content of an essential micronutrient (vitamins and minerals, including trace elements) in a food in such a way as to improve the nutritional quality of the diet and provide a public health benefit with minimal health risk [2] .

In West Africa, vitamin A fortification of oils is already underway in Ghana, Nigeria, and Côte d’Ivoire. In light of these important challenges, the Government of Senegal initiated the fortification process, which resulted in the adoption of Senegalese standards for vitamin A-fortified edible oils and soft wheat flour fortified with iron and folic acid. To effectively combat micronutrient deficiency, it is necessary to make the fortification of these products mandatory and enforce the relevant standards [3] .

Preformed vitamin A, or retinol, is exclusively of animal origin. Carotene or carotenoids act as provitamins. Of the many plant carotenoids, the most important is beta-carotene, which is converted to vitamin A by enzymatic action in the intestinal wall [2] . Dietary vitamin A deficiency primarily affects the eyes and can lead to blindness. Xerophthalmia, or dry eyes (from the Greek xeros = dry), is the term that covers the various effects of deficiency. Vitamin A deficiency also affects other organs and contributes to increased childhood mortality, especially in cases of measles [3] .

Inadequate intake of carotene or preformed vitamin A, poor intestinal absorption, or increased demand are the three causes of deficiency, the first being by far the most common.

The best sources of retinol are liver, fish liver oils, egg yolk, and dairy products. However, in developing countries, most poor people get up to 80 percent of their vitamin A intake from carotene in plant foods. This carotene is a yellow pigment, but it can be masked by chlorophyll in dark green leafy vegetables, for example. It is found in many green and yellow vegetables and fruits, in yellow corn, and in some yellow roots such as sweet potatoes. Another very rich source is palm oil, which is commonly consumed in West Africa but is not widely consumed [3] .

Vitamin A deficiency is the leading cause of blindness in many endemic areas. Xerophthalmia is usually due to insufficient intake of vitamin A and beta-carotene over a prolonged period. Other factors that can aggravate matters include intestinal parasites, gastroenteritis, or malabsorption. Measles usually precipitates the progression to xerophthalmia through anorexia and stomatitis, which further reduce dietary intake and increase vitamin A requirements. In addition, the virus can directly affect the eye and aggravate damage due to vitamin A deficiency [3] .

Vitamin A, preformed or transformed from beta-carotene, is stored in the liver and then transported to other organs by its carrier protein, RBP (Retinol Binding Protein). A protein deficiency can therefore increase a vitamin A deficiency by reducing the synthesis of RBP. The biological activity of vitamin A is now expressed in retinol equivalents (RE) rather than international units (IU). One RE is equivalent to 1 µg of retinol or 6 µg of beta-carotene. The WHO recommends an intake of 300 RE per day for children and 750 RE for adults [3] . According to the long-term preventive approach, the prevention of deficiency is based on increasing the production and consumption of foods rich in vitamin A or carotene by vulnerable populations, coupled with nutritional education. In the meantime, supplementation with massive doses of vitamin A every four to six months can be used, or fortification of certain foods can be considered [3] .

Vitamin A is essential for good vision and cell differentiation. Deficiency leads to growth retardation, mucosal damage, reproductive disorders, eye damage, and ultimately blindness. Children with vitamin A deficiency are often deficient in several micronutrients and are likely to be anemic, growth retarded, and at increased risk of severe morbidity from common childhood infections such as diarrhea and measles. Pregnant women with vitamin A deficiency may be at increased risk of mortality. Approximately 30 percent of preschool-aged children are vitamin A deficient, and nearly 5.2 million preschool-aged children suffer from night blindness. A 2013 Lancet article attributed 105,700 infant deaths to vitamin A deficiency. More than 19 million pregnant women in developing countries are also vitamin A deficient, and 9.7 millions are clinically night blind [4] .

It is in this context that Senegal has committed itself through this ministerial decree Decree No. 2009-872 of September 10, 2009 making mandatory the application of standards on refined edible oils enriched with vitamin A and soft wheat flour, enriched with iron and folic acid. To launch the promotion of foods enriched with vitamin A constitutes one of the key interventions of the strategic plan to combat child malnutrition and women of childbearing age and vitamin A supplementation to reduce the risk of anemia by improving hemoglobin and ferritin levels [5] . Moreover, good nutrition constitutes a major determinant of health and a key factor for the development of a country because it is an essential condition for the physical, mental and psycho-affective growth of the individual [6] . The aim of this study was to evaluate the vitamin A content by the laboratory analytical method in order to be in line with the will of the Senegalese state concerning its policy towards the compulsory enrichment of refined vegetable oils with vitamin A.

This was a cross-sectional quantitative study conducted from June to July 2022.

The study covered three areas, namely three districts in the city of Dakar. The choice was made due to the high demographic concentration of Dakar’s population; the municipalities of Grand-Yoff, Pikine, and Keur Massar were selected based on population density.

The shops were randomly selected, three at least 1 km apart. A total of ten types or brands of vegetable oil were listed in each location, for a total of thirty (30) samples across the three municipalities. The samples were hermetically sealed with aluminum foil to prevent contact with UV rays and sent to the analysis laboratory.

The results are expressed in mg/kg of oil, as summarized in Table 1 below;

GY = Grand-Yoff, KM = Keur Massar, PIK = Pikine, HVS = Huile végétale Soja, HVT = Huile végétale Tournesol.

The oils marketed in Senegal come on the one hand from national production which is industrial with Sonacos and on the other hand from imports to cover the needs of consumers in the Senegalese market which is too large, in addition there is an artisanal production which is less despite awareness efforts to curb this practice which does not offer all the guarantees in terms of hygiene and food safety. Faced with the diseases of xerophthalmia, vitamin A deficiency and anemia, which primarily affect young children and women of childbearing age, Senegal has enrolled in the vitamin A oil fortification program, through Decree No. 2009-872 of September 10, 2009, making mandatory the application of standards on refined edible oils enriched with vitamin A and soft wheat flour, enriched with iron and folic acid.

In West Africa, the fortification of oils with vitamin A is already effective in Ghana, Nigeria and Ivory Coast. In view of these important issues, the Government of Senegal has initiated the fortification process which resulted in the adoption of Senegalese standards on edible oils fortified with vitamin A and soft wheat flour enriched with iron and folic acid [2] . The aim of this study was to evaluate the vitamin A content which is in perfect alignment with the policy defined by the State of Senegal on the mandatory fortification of refined vegetable oils with vitamin A on the one hand, and on the other hand to alert and define a new trajectory to allow the surveillance and regular monitoring of the health control plan on foodstuffs marketed on the Senegalese market with the support of competitiveness to satisfy the strong aspiration of the population for better well-being [14] . This will involve, among other things, diversifying the productive base to strengthen the resilience of the economy through agro-industry and industrial development by establishing the best long-term resilience which would consist of diversifying sources of production and improving growth [15] .