Chapter 1: Background to the Study
This chapter forms the basis of the research by providing a background to the study with respect to the diet of women during early pregnancy. The chapter also discusses the research aims and objectives as well as the research hypotheses. In aIDition, the rational for the study is provided together with the overall organization of the dissertation.
Nutrition among pregnant women is a significant public health issue; this is because poor nourishment can result in a number of health issues such as obesity, overweight, cancer, diabetes and cardiovascular disease (Signore et al. 2008; Cheng et al. 2008; Shaw et al. 2004; Ueland 2010). Malnourishment during pregnancy plays a pivotal role in the causing stillbirths before commencement of labor. Cheng et al. (2008) points out that pregnancy is often typified by supplementary energy requirements of about 300 kcals on a daily basis (1256 Kilojoules), with changes in energy metabolism during pregnancy together with significant variations among women. As a result, health dietary intake during pregnancy is vital to for the health outcomes of both mothers as well as their infants. Cho et al. (2010) emphasizes that the most demanding period during human growth and development takes place in the course of the 9 months of pregnancy. Evaluating the nutrient and food intake during pregnancy is complicated since conception usually sets off a myriad of sequential and complex physiological changes that are likely to have an impact on maternal nutrient metabolism and absorption, meal patterns, appetite and nutrient and energy needs (Allen 2006). Individual behavioral physiological responses with regard to the stress of reproduction usually vary considerably, and that both the amount and type of food intake changes in accordance with the pregnancy period (Meck & Williams 2003). Nausea, which is prevalent in about 50-80% of pregnancies, is likely to commence as early as 4-6 weeks of gestation and peaks during 8-12 weeks, after which it declines. Constipation and heartburns are also known to prompt changes in the eating habits (Bidulescu et al. 2009; Leslie et al. 2010). Cho et al. (2010) reports that women are likely to develop food preferences during pregnancy because of the changes with respect to smell and taste. Another food disorder, Pica, is typified by the urge to eat non-food substances, and usually affects at least 50% of pregnant women in the United Kingdom. Maternal concerns regarding parenting, weight gain and fetal growth and development is likely to increase the maternal awareness regarding nutrition and increase the focus of the healthcare provider towards food habits as well as supplement consumption (Wen et al. 2010).
Wen et al. (2010) reported that nutrition during pregnancy has a considerable impact on infant growth and development. For instance, high intake of folic acid prior to and throughout pregnancy has been established to hamper the development of defects in the neural tube (King 2000). Similarly, excessive intake of vitamin A during early pregnancy is teratogenic to the fetus. Innis & Elias (2003) conducted an extensive data review regarding pregnancy and recommended nutrient supplementation, dietary intake and weight gain. The authors inferred that pregnant women ought to gain body weight depending on their pregravid body mass index (BMI), be counseled about the required healthy diet needed to gain weight, and examined on a regular basis in order to determine any potential problems. In aIDition, the study also recommended pregnant women to undertake regular dietary intake assessment in the course of the pregnancy. Evidence suggests that maternal nutrition prior to and during pregnancy have a significant on the fetus during and after birth (Innis & Elias 2003). In aIDition, most women often become interested in their heath following the confirmation of pregnancy. Meck & Williams (2003) reported that pregnant are more apprehensive about their body image and weight; however, most women usually enter pregnancy with relatively lower levels of calcium intakes than the recommended 100 mg per day. A study by Innis & Elias (2003) reported that, after pregnancy confirmation, most women usually attempt to increase the intake of calcium. In aIDition, Innis & Elias (2003) reported that pregnant women usually eat better during the early phases of the pregnancy; nonetheless, this trend does not necessarily continue with the changes taking place in the course of the pregnancy.
Malnutrition during pregnancy is caused by insufficient dietary intake, which is linked to a number of socio-cultural and economic variables. Innis & Elias (2003) proposed a measure of poor nutrition during pregnancy: less intake of vegetables and fruits than the recommended intake. A study by Wen et al. (2010) reported that only 10% of the population consumes the recommended 5 or more serves of vegetables on a daily basis, and about 50 percent reported to consume the recommended 2 or more serves of fruits on a daily basis. There is no doubt that social economic status plays a pivotal role with regard to nutritional intake by pregnant women. Innis & Elias (2003) reports that individuals with higher socio-economic status are closer to the nutritional recommendations that their counterparts from lower socio-economic status.
However, to date, there is a limited prevalence data with respect to diet related health behaviors exhibited by pregnant women. This poses the need to explore the trends in dietary intake among pregnant women, especially those in the early phases of their pregnancy (Albright et al. 2005; Allen 2006; Bidulescu et al. 2009). In this regard, the focus of this study is to assess choline intake, through egg consumption, among women in their early pregnancy phases. Cho et al. (2010) reported that choline consumption is a prerequisite for a healthy body. Choline helps in the production of constructional components found in the cell membranes of the human body (Zeisel 2006; Xu, Gammon & Zeisel 2009). Regardless of its potential benefits associated with choline intake, nutritional recommendations do not encourage the consumption of particular high-choline food substances such as fatty meats and eggs. A survey by Innis & Elias (2003) reported that only 2 percent of women in post menopause eat the recommended choline-intake. In this regard, this study will assess the trends in choline intake among women in early pregnancy.
1.2 Aims and Objectives
The primary objective of this study is to assess choline intake among women in early pregnancy. In this regard, the study seeks to determine the percentage of women in early pregnancy consuming the recommended choline intake as well as the differences between the patterns of consumption. The following are the specific discussion objectives of this study:
To determine the proportion of women in early pregnancy taking the recommended choline intake;
To determine the prevalence of both low and high choline intake among women in early pregnancy;
To explore the factors that influence choline intake among women in early pregnancy.
1.3 Rationale for the Study
As aforementioned, choline intake plays a pivotal role in determining the health outcomes for both mother and as well as her infant (Cheng et al. 2008). In this regard, this study will play a significant role in aIDressing a public health issue, nutrition of pregnant women, through determining the prevalence of recommended, high and low choline intake among women in early pregnancy. As a result, the findings of this study will provide important insights as regards the nutrition of pregnant mothers. Public health institutions and healthcare givers will make use of the findings presented in this study to devise measures to ensure that women in early pregnancy consume the suggested choline intake.
1.4 Research Plan
This research plan details the organization of this dissertation. Chapter 1 has provided a background of the study with respect to nutrition among pregnant women. The chapter has also spelled out the aims and objectives and the rationale for the study. Chapter 2, literature review, discusses existing literature regarding choline intake during pregnancy. Chapter 3, research methodology, discusses the methodology used in this research, which included the research designs and their respective justifications, the research philosophy, sampling techniques, participants and the data collection methods. Chapter 4, data analysis and presentation, presents the findings of the study and makes subsequent interpretations basing on the aims and objectives of the research. Chapter 5, conclusion and recommendations, summarizes the study and makes recommendations basing on the implications of the findings on public health. In aIDition, the chapter outlines discusses the limitations associated with the findings and makes recommendations for future studies.
Chapter 2: Literature Review
This chapter reviews current and critical literature regarding choline intake among women in early pregnancy. The chapter discusses the role of choline, recommended daily intake as well as the trends in choline intake among women in pregnancy.
Choline has been established to a crucial nutrient in the Vitamin B category and can be found in foods such as wheat germ, lentils, bananas, white fish, salmon, soybean, kidney, cauliflower, milk, bacon, spinach and eggs (Caudill 2010; Buchman et al. 2001; Signore et al. 2008). The Adequate Intake levels (AIs) for choline was first established in 1998 by the National Academy of Sciences. Despite the fact that choline has been incorporated recently in the vitamins’ family, it has been investigated by nutritionists for about 15 decades (Ueland 2010). Thomas et al. (2007) affirmed that major research discoveries regarding choline were evident during the late 1930s, at a time when scientists made a discovery that a tissue in the pancreas produced a substance that could be of significant help in preventing the build-up of fats in the liver. The discovered substances was given the name Choline, which was derived from the Greek work Chole, meaning bile. After its discovery in the 1930s, scientific research has proved that choline is not only present in the liver and pancreas, but also a vital component found in every cell in the human body (Molloy, Mills & Cox 2005; Fisher, Zeisel & Mar MH 2002).
According to Bjelland et al. (2009), the naming of choline after the Greek word meaning bile was extremely fitting; this is because, bile, which is produced in the human liver, has the main function of converting fact to be compatible with water in order to ensure that substances that are fat-based could be moved around the body using the water-like human blood (Shaw et al. 2004). Bjelland et al. (2009) pointed out that choline has the same fat-modification effects, although in the cell membranes. In this regard, choline’s fat-modifying properties enable the human cell membranes to function with improved flexibility especially with regard to the handling of fat-soluble and water-soluble molecules. In the absence of choline, most fat-based nutrients as well as waste products could not be transported in and out of the human cell (Zeisel 2006; Wen et al. 2010; Veenema, Solis & Li 2008). Besides its distinctiveness as a substance that modifies fat, choline is also chemically distinctive as a trimethylated molecule (Cho et al. 2010). The phrase methylated refers to a substance having a minimum of one special group known as the methyl group, which is attached to the substance. Choline has been proven to be trimethylated, which means that it has 3 methyl groups attached to it (Cho, Willett & Colditz 2007). Several crucial chemical processes taking place in the human body are facilitated by the transport of methyl groups around the body. For instance, genes in the human body are turned on and off using this mechanism, and human cells utilize the same mechanism to relay messages back and forth. With regard to mental health, wherein the messages relayed between nerves are crucial, choline has emerged to be a substance of significant interest for researchers (Detopoulou et al. 2008; Fischer, daCosta & Kwock 2007; Bjelland et al. 2009).
According to Meck & Williams (1997), choline plays a crucial role among pregnant women, especially with regard to fetal brain development. Meck & Williams (1997) emphasized dietary consumption of choline in order for the human body to stay healthy; this is because choline helps in the production of constructional components found in the human body. Regardless of the nutritional benefits linked to choline intake, dietary recommendations discourage the intake of particular high-choline food substances such as fatty meats and eggs. A survey by Wen et al. (2010) reported that only 2 percent of women in their post-menopause consume recommended intake.
2.2 How Choline Functions
2.2.1 Maintaining Cell Membrane Integrity
Choline is a vital component of the various fat-based structures found in the cell membrane. Owing to the fact that fats are the main component of the cell membranes, the integrity and flexibility of the human cell membrane relies significantly on the sufficient availability of choline (Thomas et al. 2007; Zeisel 2009; Cho et al. 2010). Structures found in the membrane that need choline include sphingomyelin and phosphatidylcholine. In the human brain, the fat-like molecules make up a significant proportion of the total solids found in the brain, which makes choline extremely vital for brain health, and useful in the treatment of brain disorders (Morgane, Mokler & Galler 2002).
2.2.2 Supporting Methyl Group Metabolism
The chemical uniqueness of choline as a trimethylated substance makes it extremely vital in the metabolic processes involving the methyl group (Albright et al. 2005). Methyl group refers to a chemical structure having only 1 carbon atom together with 3 hydrogen atoms; thus, a methylated substance has a minimum of one methyl group (Albright et al. 2005). Choline has 3 methyl groups. As aforementioned, several vital chemical processes in the body are facilitated through the transfer of methyl groups around the body, which makes choline play a vital role in the methyl group metabolism (Detopoulou et al. 2008).
2.2.3 Supporting Nervous System Activity
Choline has been established to a vital constituent of acetylcholine, which is a messenger molecule in the nervous system (Craciunescu et al. 2004; Das et al. 2005). Sometimes referred to as neurotransmitter, acetylcholine relays messages back and forth between nerves, and the main chemical mechanism that the human body uses to transmit messages between muscles and nerves. Owing to its important role in supporting muscle-nerve function, choline has been experimentally utilized to help in improving in neuromuscular functioning among Alzheimer patients (Gossell-Williams et al. 2005; Meck & Williams 2003).
2.2.4 Lessening Chronic Inflammation
Detopoulou et al. (2008) reported that people with dietary intake characterized by high levels of choline intake (found in soybeans and egg yolk) have 20 percent lower inflammatory markers when compared to individuals with relatively low average choline intake. When compared to individuals who dietary intake of choline was less than 250 mg per day, participants whose dietary intake of choline was more than 310 mg per day reported 22 percent lower concentrations of the C-reactive protein, 26 percent lower concentration of interleukin-6, and 6 percent lower concentrations of necrosis factor alpha (Detopoulou et al. 2008). The same study compared individuals who consume less than 260 mg per day of betaine (a metabolite of choline) with participants whose dietary intake of betaine is more than 360 mg per day. The findings reported that those consuming at least 360 mg of betaine on a daily basis had 10 percent lesser concentrations of honocysteine, 19 percent lesser concentration of C-reactive protein, and 12 percent lesser concentrations of tumor necrosis factor alpha (Detopoulou et al. 2008). It is imperative to note that the inflammatory markers used in the above study have been associated with a number of conditions such as type-2 diabetes, Alzheimer’s disease, cognitive decline, and osteoporosis. From the study, Detopoulou et al. (2008) concluded that choline is a new food substance in the Mediterranean diet that helps in lessening inflammation. Detopoulou et al. (2008) noted that betaine and choline work collectively during methylation, which is a cellular process used to remove homocysteine and also helps to turn off the promoter regions of human genes taking part in inflammation. Detopoulou et al. (2008) also noted that choline is a dietary approach that can be used to reduce the prevalence of chronic diseases linked to inflammation.
2.3 Deficiency Symptoms Associated with Choline
The link between health and choline is evident through the impact that choline deficiency has on the risk of cardiovascular problems including the coronary heart disease (CHD) (Bjelland et al. 2009; Hale & Hartmann 2007; Mellott et al. 2004). According to Veenema, Solis & Li (2008), the risk of coronary heart disease and other circulatory/heart problems is linked to high blood concentrations of homocysteine. Several factors can result into high homocysteine levels in the blood; however, choline deficiency plays a pivotal role in increasing homocysteine concentrations since choline helps in the conversion of homocysteine into other substances, which in turn, prevents build-up (Albright et al. 2005; Bjelland et al. 2009; Cheng et al. 2008).
Molloy, Mills & Cox (2005) reported that a mild choline deficiency can be associated with muscle-nerve imbalances, memory problems, inability of the kidney to concentrate urine, insomnia and fatigue. In aIDition, choline deficiency has also been established to result in the deficiency of folic acid, which a critical vitamin B component required for good health (Molloy, Mills & Cox 2005). On the other hand, acute dietary choline deficiency can lead to high blood pressure, anemia, kidney failure, respiratory problems among newborns, infertility, impaired red blood cell formation, abnormalities with regard to bone formation, impaired growth, cardiovascular disease, and liver dysfunction (King 2000; Gossell-Williams et al. 2005; Meck & Williams 2003). In instances of respiratory distress and high blood pressure, the effect of dietary choline deficiency is likely to result in lack of acetylcholine in the nervous system, which cannot be synthesized in the absence of choline. In instances of red blood cell formation and kidney failure, choline deficiency is linked to inadequate phosphatidylcholine, which is a component of the cell membrane that cannot be produced in the absence of choline (Morgane, Mokler & Galler 2002). In aIDition, deficiency of dietary choline can be linked a breakdown with respect to fat metabolism and transport, which is likely to increase the unavailability of fat as a source of energy. Signore et al. (2008) reported that the impacts of choline deficiency are especially evident in the liver because insufficient choline hinders the liver from transporting and packaging fat-based substances in a natural pattern. The main symptom associated with this alterations in the fat packaging and transport system is a reduction in the level of VLDL (very low density lipoprotein), which is a fat-based molecule used in the transportation of fat. The outcome is a buildup of fat in the liver. According to Allen (2006), endurance athletes, people drinking alcohol, vegans and vegetarians are at risk of suffering from deficiency of choline; as a result, they should make use of choline supplements. Several studies conducted on diverse populations have reported that the average dietary choline intake is below the recommended adequate intake (Allen 2006; Zeisel 2009). When analyzing data from National Health and Nutrition Examination Survey 2003-2004, Zeisel (2009) pointed out that pregnant women, women, men and older children had mean dietary intakes that are relatively below the recommended Adequate Intake. The analysis by Zeisel (2009) revealed that only 10% had the dietary choline intake equal to or above the Adequate Intake.
2.4 Choline Toxicity Symptoms
Zeisel (2006) linked high choline intake (10-15 grams per day) to increased sweating and salivation, vomiting and body odor. The symptom associated with unpleasant body odor has been linked to an increase in the levels of choline product known as trimethylamine. Intake of choline of 5-10 grams daily has also been linked to dizziness, faintness, and reduced blood pressure in some people. The National Academy of Sciences came up with a Tolerable Upper Intake Level for choline of 3.5 grams daily, which was based mainly on the risk associated with reduced blood pressure (Zeisel 2006).
2.5 Nutritional Significance of Choline
Several empirical studies have affirmed that nutrient availability affects the development of vital parts in the human brain as well as having an effect on brain development during later stages in life (Allen 2006; Fischer, daCosta & Kwock 2007; Meck & Williams 2003; Veenema, Solis & Li 2008). Cheng et al. (2008) reported that choline is required to ensure signaling functions and structural integrity of the human cell membrane. In aIDition, choline has a direct influence on lipid metabolism and transport, transmembrane signaling and cholinergic neurotransmission. According to Cho, Willett & Colditz (2007), the presence of choline in diet has an impact on the development of hippocampus, closure of the neural tube, apoptotic signaling in liver cells and neurons, and hepatic carcinogenesis. The National Academy of Sciences in the United States established a sufficient choline intake amount of 425 milligrams daily for women and 550 milligrams daily for men. According to Meck & Williams (2003), women in pregnancy are the most susceptible to the availability of dietary choline owing to the significantly increased requirements for choline needed to form and develop the fetus. The following subsections discuss the dietary and health benefits associated with choline.
2.5.1 Brain Health
Sphingomyelin and phosphatidylcholine are two vital lipid molecules produced from choline and play a crucial role in insulating the nervous system electrical circuitry (Meck & Williams 1997; Mellott et al. 2004). In case these insulators are unavailable, electrical signals transmission in nerves is likely to slow down resulting in several neurons becoming short-circuited. A significant proportion of the weight of the central nervous system comprises of these two molecules. Choline is also used in the synthesis of acetylcholine, which is also an important substance in brain is functioning. Acetylcholine, an important neurotransmitter, is responsible for relaying signals from the spinal cord and brain to the lungs, the heart, muscles, glands and the gastrointestinal tract (Caudill 2010; Innis & Elias 2003; Shaw et al. 2004; Morgane, Mokler & Galler 2002). Acetylcholine plays a pivotal role in normal memory development as well as ensuring consciousness (Gossell-Williams et al. 2005). Morgane, Mokler & Galler (2002) conducted a study to explore the role that choline plays in brain development and health on rats’ offspring fed using diet that is choline deficient. The study pointed out that, rats whose mothers had inadequate dietary choline had poorer brain development and memories when compared to rats whose mothers had adequate choline (Morgane, Mokler & Galler 2002). Recent scientific studies have also hinted that choline can help in preventing memory loss linked to aging. Despite the fact that foliate is the only nutrient thought to have the capability to prevent defects in the neural tube, scientific research has uncovered the role that choline plays in preventing the same (Shaw et al. 2004).
2.5.2 Liver Heath
Buchman et al. (2001) reported that choline is needed to eliminate surplus fats and cholesterol found in the live. Deficiency of dietary choline results in the accumulation of fat droplets in the liver resulting to hepatosteatosis. In aIDition, sufficient dietary choline intake can also be used in reversing the hepatosteatosis after it occurs (Ueland 2010).
2.5.3 Pregnancy Health
Besides from guaranteeing the normal development of the nervous system in the growing fetus, Detopoulou et al. (2008) reported that choline also helps in preventing the developments of congenital heart defects in infants. It is vital for pregnant women to have adequate choline; this is because low intake of dietary choline has been established to increase the likelihood of neural tube defects among infants, and is likely to have an impact on their memory. Shaw et al. (2004) reported that choline dietary intake before and after giving birth is related with a reduced risk of neural tube defects. Zeisel (2009) also pointed that low choline dietary intake increases the level of homocysteine, increases the risk of preeclampsia, extremely low birth weight and premature birth. In aIDition, Xu, Gammon & Zeisel (2009) reported that women consuming higher dietary choline are less likely to suffer from breast cancer.
2.5.3 Inflammation Reduction
Several studies have affirmed that the amounts of inflammatory markets such as tumor necrosis factor-alpha, interleukin 6 and C-reactive protein can be reduced by 20% through the consumption of adequate dietary choline (Detopoulou et al. 2008; Gossell-Williams et al. 2005; Veenema, Solis & Li 2008). Homocysteine, which is also an inflammatory marker, can also be lessened through high consumption of dietary choline. According to Detopoulou et al. (2008), choline’s function as a methyl donor helps in the degradation of homocysteine as well as turning off DNA regions used to express the inflammatory markers.
2.6 Food Sources of Choline
According to Allen (2006), the richest choline source in the Mediterranean diet is not derived from food; rather, it comes from an aIDitive referred to as lecithin (phosphytidylcholine). Meck & Williams (1997) pointed out that lecithin is usually aIDed to food substances in the form of an emulsifier, which is a substance used to facilitate the blending of food components. In the Mediterranean food supply, most lecithin is derived from soybeans. Although there is no adequate research to group choline food sources basing on the “good, very good, and excellent” rating system, the known food choline sources are egg yolk, soybeans as well as soybean products, whole wheat bread, flax seeds, sesame seeds, corn, barley, oats, lentils, oranges, milk, banana, tomatoes, cauliflower, potatoes, peanut butter, peanut and butter (Gossell-Williams et al. 2005; Mellott et al. 2004; Wen et al. 2010). It vital to note that most of these food sources have choline itself as well as other forms of choline such as sphingomyelin and phosphatidylcholine. The following table 1 shows the food sources.
Plant and animal foods
Sunflower lecithin syrup (32g)
Raw beef liver (142g)
Soy lecithin granules (15g)
Chicken (0.5 pound)
Cod fish (227g)
Quart of milk, 1 percent fat
Brewer Yeast (30g)- 2 tea table spoons
Wheat germ (1 cup)
Firm tofu (0.47 liters) – 2 cups
Cooked kidney beans (2 cups)
Uncooked amaranth (1 cup)
Uncooked quinoa (1 cup)
Peanuts (146g) – 1 cup
Cooked brown rice (3 cups)
Source: Hale & Hartmann (2007)
2.7 Adequate Choline Intake
The Adequate Intake Levels for choline together with the Upper Limits are shown in the table below.
Adequate Intake (milligrams per day)
Upper Limit milligrams per day)
0 – 6 months
7 – 12 months
1 – 3 years