The median daily choline intake from food sources was 275.0 mg in this sample of pregnant women. Almost all participants consumed less choline than the AI recommends. Anecdotal evidence suggests that choline is usually not added to MVM supplements, and very few brands available in most South African shops and pharmacies contain choline. A Canadian study found that none of the prenatal supplements that were used contained choline . Additionally, MVM supplement use was not common in this sample; thus, it can be concluded that participants in the current study relied on food sources for choline intake. A population level choline intake below the AI has been reported by various researchers, from both developing [11, 24, 25] and developed [1, 10, 26, 27] countries. Based on the important functions of choline during pregnancy, especially related to foetal growth and development (Korsmo & Jiang, 2019:4), the population groups that are most likely to benefit from adequate choline intake are pregnant women and their offspring.
Food sources of choline
Choline is found in a variety of foods; however, animal products generally have higher levels of choline than plant products. Good sources of choline include eggs, beef, chicken, fish, dairy, cruciferous vegetables, certain beans , as well as beef liver, chicken liver, wheat germ, dried soybeans and pork . In the current study, food groups that contributed most to choline intake, included meat, cereals, eggs and dairy. This is in agreement with the established good food sources of choline, as well as with research done in European populations .
In the current study, full-cream milk, maize meal, brown bread, fried eggs, slap chips (deep fried potatoes) and vetkoek (deep fried dough) were among the top foods that contributed to choline intake. However, individual food items that contributed most to choline intake were influenced by the amount of the food item generally consumed, not simply the choline density. Food items that are considered to be poorer sources of choline, but were consumed in high amounts, were among the top contributors of choline in this sample of pregnant women. For example, bread, maize meal, apples and bananas are not good sources of choline, but were consumed relatively frequently and in large quantities and as such, could be regarded as important sources of choline in the diet of this population. This important aspect must be considered when promoting the intake of choline in populations from different countries, as eating habits differ significantly among cultures. In addition, many of the top choline contributing foods in this sample are not generally considered to be health-promoting foods, as processed, high-fat, high-salt foods featured prominently (fried egg, deep fried dough, beef sausage, fried pork sausage, white bread, white rice, cold drinks). Thus, these foods might have contributed to choline intake, but regular consumption thereof can contribute to obesity and other non-communicable diseases (NCDs) as well as micronutrient deficiencies in general. Intake of healthier sources of choline, such as boiled eggs, lean meat, dairy and wholegrain products should be promoted among pregnant women.
In the current study, eggs in general, and fried eggs specifically, were some of the top foods or food groups that contributed to choline intake. However, many participants did not consume any eggs. Eggs are exceptionally high in choline; thus, the regular consumption of eggs may contribute substantially to choline intake. In the current study, inadequate choline intake was significantly associated with lower egg consumption (p < 0.0001), supporting this supposition. Additionally, the odds of consuming an inadequate amount of choline increased substantially as egg intake increased. In general, egg consumption in South Africa has increased by 55.8%, from 1994–2009, and by 24.1%, from 1994–2012. Per capita egg consumption in 2012 was 7.2 kg per year , which translates to three large eggs per person per week. The South African Food Based Dietary Guidelines (SAFBDGs) recommend an egg intake of “approximately four eggs per week” . Culture and food taboos may influence the consumption of foods such as eggs, and this phenomenon is also common during pregnancy. Chakona and Shackleton (2019) investigated the influence of food taboos and beliefs on food choices among pregnant women in the Eastern Cape, South Africa. They found that eggs were among the most commonly avoided foods during pregnancy, along with meat, fish, potatoes, fruits, beans and pumpkin. The authors suggest culturally appropriate education for this population with the goal of improving nutrient intake to optimally support requirements during pregnancy . Socioeconomic status and the price of eggs might also influence egg consumption. A study by Headey et al. (2017) to investigate animal sourced foods and child stunting, showed that eggs are a relatively inexpensive source of nutrients in higher income countries. However, the authors state that in Africa eggs are nine to ten times more expensive than staple cereals .
Although most participants consumed dairy, it was mostly consumed in relatively small amounts (< 1 cup per day). The SAFBDGs specifically recommend a daily intake of 400–500 ml low-fat milk for all adults . Although, per weight, dairy products are not as high in choline as eggs, they can contribute substantially to choline intake if consumed frequently. A lower dairy intake was significantly associated with inadequate choline intake in the current study (p = 0.0002), and the odds of consuming an inadequate amount of choline increased as dairy intake decreased. Additionally, full cream milk was the one specific food item that contributed most to choline intake, suggesting that dairy can contribute meaningfully to choline intake in this population. Consumption of dairy in South Africa has increased by 8.4% from 1994–2009, and by 14.7% from 1999 to 2012. Increases were observed especially for yoghurt and cultured milk consumption, and to a lesser degree, for cheese and fluid milk .
Animal derived foods are generally the top contributors to choline intake in the diets of most populations. Currently, there is widespread promotion of plant-based foods, together with the recommendation of limiting animal derived foods. These recommendations are based on the prevention of NCDs as well as contributing to sustainable and environmentally friendly food production systems . However, the reduction in consumption of animal derived foods may inadvertently lead to a reduction in the intake of certain important nutrients, including choline, which is an important factor to consider specifically in pregnant women and young children. Additionally, infants and young children who consume nutritionally inadequate diets are at risk of developing malnutrition and associated hepatic steatosis . Research has shown that the development of malnutrition-associated hepatic steatosis was prevented by choline supplementation in mice dams . The authors concluded that inadequate choline intake may increase the risk of hepatic steatosis in undernutrition. In a country such as South Africa with high prevalence of undernutrition, the implications of further limiting the intake of animal protein may be far-reaching.
South Africa is a low-resource country with a high burden of both communicable and non-communicable diseases, and strategies that could contribute to an improvement in population health, warrants attention. It is recommended that the adequate intake of choline during pregnancy should be encouraged in the South African population by means of public health messaging as well as possible changes in food fortification policies to include choline. Since egg and dairy intake were significantly associated with adequate choline intake, the promotion of culturally acceptable egg and dairy consumption (e.g. cultured milk) during pregnancy should be supported. The supplementation of iron, folic acid and calcium during pregnancy is currently recommended in the South African Guidelines for Maternity Care , and as choline is such an important metabolic nutrient especially for the mother and foetus, there could be, in the light of these results, a case to be made for the addition of choline to this regimen. This should however be considered after robust human clinical trials have shown consistent benefits with maternal choline supplementation, and thus more trials to investigate the effects of maternal choline supplementation are recommended. Choline supplementation in pregnant women could result in significant health benefits for the South African poulation and should be investigated further.