Master of Science in Nutrition and Dietetics Student at King's College
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Physiological Basis of Nutrition 1
Chronic Kidney Disease
Prior to working through the Chronic Kidney Disease (CKD) modules, I did not realize how interrelated diabetes, hypertension, cardiovascular disease (CVD), and CKD are. I was surprised to learn that hypertension and diabetes are the leading causes of CKD in adults, with diabetes being the most common cause.1 Additionally, I was shocked to learn that the majority of patients with CKD die of CVD-related complications vice progressing to end stage renal disease (ESRD).2 Prior to working through these modules, I never thought about CKD etiology and was not aware of how devastating CKD can be on the lives of those diagnosed, especially since CKD is irreversible and generally progressive.1 The CKD modules were clear that a healthcare team working together is ideal to ensure the best patient outcomes, as this team works together to implement interventions to reduce complications and slow CKD progression. I think the collaboration of a health care team consisting of a nephrologist, dietitian, mental health professional, and social worker in addition to community support programs and patient education will give the patient the tools necessary to empower themselves, possibly slow the progression of disease, and hopefully reduce the need for kidney replacement therapy. After learning about the interdisciplinary care approach, I reflected on my own diagnosis of Crohn’s disease and know that if a similar interdisciplinary approach is taken, IBD patient outcomes may improve dramatically. These modules also helped strengthen my weakness when it comes to understanding and interpreting lab values. It was very helpful to learn that CKD is generally diagnosed if urine albumin > 30 mg/g creatinine in additional to clinical findings, and/or if eGFR < 60 mL/min/1.73m2 for more than three months. I now feel that I understand how to read and assess lab values such as eGFR and urine albumin-to-creatinine ratio (UACR). I now know that, from a nutrition lens, declining eGFR is associated with dyslipidemia, anemia and low iron stores, mineral and bone disorders, and malnutrition.3 I also learned that additional lab values an RD must assess when reviewing the medical record of a CKD patient are BUN, electrolytes, glucose, calcium, phosphorus, albumin, serum bicarbonate, parathyroid hormone, vitamin D, hemoglobin, comprehensive metabolic panel, and complete blood count. I have made detailed notes with lab tests important for CKD, what they mean, why they are important, and what their normal ranges and abnormal ranges are for future reference and continued learning. I also intend to make flash cards so I can easily identify these lab values and what they mean. A particular lab value that stood out to me was metabolic acidosis, which was defined in the modules as a serum bicarbonate level
Effects of a protein-reduced, Nordic complementary diet on infants
1. Why do you think I chose this article for all of you to review this week? I think this article may have been chosen because protein is important for muscle and tissue development, in addition to the suggested impacts high protein consumption may have during the first 2-years of an infant’s life.1 In this article, the infants are rapidly growing, which means their muscle tissue and muscular system are developing. Roughly 40% of body protein is found in skeletal muscle, roughly 25% is found in body organs, and the remainder is found in blood and skin.2 Because protein is found throughout the human body,2 investigating the effects a protein-reduced diet may have on the development of an infant is important to understand, especially since some studies suggest that high animal protein intake during infancy may result in higher early childhood BMI, higher serum IGF-1 levels, and higher body fat percentage, which may eventually lead to obesity later in life.1 2. What is special or different about the study participants, at baselines, even before the trial starts? And might this have affected the outcomes of the trial? Why or why not? The major difference in study participants at baseline is that the age of the participants varied and were not fixed.1 Baseline for study participants started anywhere between the ages of 4 to 6 months, vice starting at a fixed age such as starting solely at 4 months, starting solely at 5 months, or starting solely at 6 months.1 The variation in age may affect the outcomes of the trial because there is a difference in infant motor skills, sensory skills, and cognitive and physical development at 4 months of age compared to infants that are 6 months of age. A 6-month-old infant may be more adventurous at trying new foods vice a 4-month-old infant. Additionally, infants aged 0-6 months require roughly 1.52 g/kg of protein daily,2 and though participants in the Nordic group (NG) were given protein-reduced, age-adjusted milk cereal drinks, cereals, and baby food, there is a size difference in a 4-month-old infant vice a 6-month-old infant. Due to this, I am not sure if the age-adjusted foods provided are enough to keep the study findings consistent due to the variation in age. 3. What is special or remarkable about the Treatment Groups? Was there enough of a difference between them to see the hypothesized effects? Why or why not? There were a few remarkable things about the treatment groups. First, attrition for body composition measurements were high at both 12 and 18 months, though was significantly higher at 18 months for the NG group vice the conventional group (CG).1 This may have thrown off study results due to a decrease in study participation. Additionally, at both the 12-month and 18-month follow-up, plasma IGF-1 was significantly lower in the NG group, BUN was also lower in the ND group, and P-Folate was higher in the ND group vice the CD group.1 Interestingly, at 12-months, the NG group had a slightly higher plasma glucose concentration and at 18-months had a lower mean hemoglobin concentration when compared to CG.1 The study significance level was set at P < 0.05. Because of this, there was enough difference between groups when it came to measuring P-Folate, BUN, and IGF-1 (p
Vitamin D in Older Adults
1. What was the Researchers’ reason for looking at vitamin D status in this way? How would your vitamin D status play a role in immune function? The Researchers looked at vitamin D status by supplementing the experiment group with a 1,000 IU vitamin D3 tablet to see if this supplementation impacts the immune function of healthy older adults. Immune function decline, decline in innate immunity, low-grade inflammation, and vitamin D deficiency may be associated with aging.1 Vitamin D plays a role in immune function as calcitriol may maintain normal cell growth, promote differentiation, and inhibit proliferation, which may result in the reduction of cancer cell growth.2 Additionally, many immune cells express vitamin D receptors (VDRs) and include activated T and B-cells, monocytes, macrophages, cytotoxic T-cells, and antigen-presenting dendritic cells.2 Autoimmune diseases may be positively impacted with vitamin D supplementation as vitamin D may downregulate synthesis of pro-inflammatory cytokines and upregulate production of anti-inflammatory cytokines.2 Additionally, adequate calcitriol may positively impact premyeloid white blood cells and stem cells, causing them to differentiate into macrophages and monocytes.2 2. Why do you think the Researchers chose the participant population they did for this study? I think the Researchers chose older adults between the ages of 55-85 as study participants because vitamin D deficiency is common in older adults.1 As adults get older, their ability to make calcitriol decreases, dietary vitamin D intake may lower, the skin decreases vitamin D production, and they may spend less time outdoors.1 Additionally, in higher latitudes (such as Coventry UK), vitamin D deficiency is also common in summertime months, which indicates vitamin D deficiency amongst older adults at higher latitudes may be vitamin D deficient year-round.1 3. In this particular study population, were there any confounding factors that needed to be carefully controlled for? Why or why not? There were confounding factors that needed to be carefully controlled for. It was important that BMI was carefully controlled for as 43% of participants were overweight or obese and 55.6% of overweight/obese participants were vitamin D deficient vice just 16.7% of the normal weight participants.1 Plasma 25(OH)D was significantly lower in participants that were overweight and/or obese, which may be due to vitamin D storage in cutaneous and visceral adipose tissue.1 Age is a confounding factor that needed to be carefully controlled for as evidence suggests the older an individual gets, the more their immune function declines, their ability to make the active form of vitamin D (calcitriol) decreases, and if they are elderly, their skin may only produce 25% of vitamin D after sun exposure compared to younger adults.1 There is a wide variation in age, as the youngest study participants were 55 years old and the oldest study participants were 85 years old. This 30-year age difference may result in variation of vitamin D absorption and storage amongst the participants. Gender is a confounding factor that may need to be carefully controlled for as studies suggest that vitamin D synthesis and metabolism may vary amongst males and females.3 Evidence suggests that when compared to men, women may be able to store more vitamin D from skin synthesis due to women having higher body fat percentages than men.3 One interesting confounding factor that I noticed was not controlled for was race. Though all but one of the study participants were white Caucasian, one participant was from South Asia (Indian Ethnicity).1 Because all participants were not the same race, I wonder if results may have changed had this been controlled for. 4. What do you think about the Researchers’ choices of Intervention? Explain how you think the treatment groups were “Different Enough” for researchers to see an effect/test their hypothesis. I think the Researchers’ choice of intervention, which was a vitamin D3 supplement tablet of 1,000 IU/day, was a great choice. Participants may be least likely to take a D3 supplement if it was administered via injection and may lose track of drops if the vitamin D3 supplement was given as a liquid that needed to be administered sublingually. Additionally, for the general public, access to vitamin D3 tablets is convenient for supplementation. Due to these reasons, my assessment is that the D3 supplementation tablet is the most convenient choice not only for study participants, but also for the general public. The treatment groups were different enough as they were stratified and divided into two groups – a vitamin D supplementation group and a control group. The supplementation group was provided D3 tablet supplements of 1,000 IU each and also given a vitamin D education leaflet whereas the control group was only given the vitamin D education leaflet.1 Additionally, the vitamin D supplementation group was given 100 tablets in a bottle and asked to return the bottle at their last visit, where Researchers then counted the left over tablets to check for compliance. After all bottles were returned, it was found that over 75% of participants consumed more than 80 tablets, which, when compared to the required amount of 84, suggests good vitamin D compliance amongst study participants. The other 25% of the supplementation group consumed between 70-79 of the 84 required tablets, which is still decent compliance overall. At baseline, the vitamin D supplement group had higher plasma 25(OH)D amounts than the control group and as the study progressed, plasma 25(OH)D significantly increased from baseline to week 6 and baseline to week 12, though plasma 25(OH)D did not change between weeks 6 and 12.1 However, the plasma 25(OH)D of the control group remained stable throughout the duration of the study.1 Due to these results, there were plenty of differences between the two groups. When it comes to the stratified groups of age, gender, and BMI there were enough differences as vitamin D absorption, storage, and deficiency may be much different in the 55–65 age group when compared to the 76-85 year old age group. The 75-85 year old group may be considered elderly and may be less active and consume less dietary vitamin D3 than the 55-65 year old group. Additionally, females and males may metabolize and produce vitamin D differently, so there were enough differences amongst this stratified group. Lastly, evidence suggests that overweight/obese individuals tend to have lower vitamin D levels, and in this specific study, 55.6% of overweight/obese participants were vitamin D deficient. Due to this, stratifying groups by BMI make sense. Due to these reasons, there were enough differences between both the vitamin D supplementation group and control group, in addition to the three different stratified groups. 5. How would you translate the research findings, in a graphic or picture? I decided to translate the research findings through a meme graphic. I have found memes work well when trying to explain nutrition to social media audiences. Please take a look at the attached meme below and let me know what you think! References 1. Dong H, Asmolovaite V, Farnaud S, Renshaw D. Influence of vitamin D supplementation on immune function of healthy aging people: A pilot randomized controlled trial. Front Nutr. 2022;9:1005786. Published 2022 Nov 1. doi:10.3389/fnut.2022.1005786 2. Gropper SS, Smith JL, Carr TP. Advanced Nutrition and Human Metabolism. 7th ed. Boston, MA: Cengage; 2018. 3. Wierzbicka A, Oczkowicz M. Sex differences in vitamin D metabolism, serum levels and action. Br J Nutr. 2022;128(11):2115-2130. doi:10.1017/S0007114522000149
Final thoughts
The studies that stood out to me when I changed my way of thinking was the week 2 assigned study from Johansson et al (RCT of a Nordic, protein-reduced complementary diet in infants)1 and the week 3 assigned video/study by Kelly et al (Associations between types and sources of dietary carbohydrates and cardiovascular disease risk).2 I used to think that consuming a “variety of nutrients” was the healthiest diet to follow. I would say things like, “Eat nutrient dense foods” or “Eat a variety of nutrients” without realizing how incorrect and nonspecific these phrases are. I used to think a “nutrient rich diet” would naturally result in favorable health outcomes. For example, when I read the study by Johansson et al on a Nordic protein-reduced complementary diet in infants,1 I thought the infants in the Nordic group were exposed to a variety of nutrients rather than exposed to a variety of foods because I thought that individual foods and the nutrients that make-up each respective food was interchangeable. Because I used to incorrectly refer to food as “nutrients,” I also unknowingly negated the fact that food groups exist. But now, I think that we consume food, and the variety of foods we consume makes up our overall dietary eating pattern. I now know we do not eat nutrients. This mindset shift helped me realize that we are obtaining energy from the foods we consume, and that the nutrients absorbed from consuming food comes from macronutrients and micronutrients. When this mindset shift occurred, I realized that the infants in the Nordic group did not consume nutrients, they consumed food. I also realized that these infants consumed a variety of foods from a variety of food groups (fruits, vegetables, protein, milk, and grains) and that this consumption of food made up their overall dietary pattern. The dietary pattern was not made up of a “variety of nutrients” consumed. Overall, I now know that these infants were not fed “nutrients” but instead were fed foods, and by consuming those foods they absorbed the nutrients, and the absorption of nutrients may be reflected in their biochemical data. I now realize that “food” and “nutrient” are not interchangeable. I have distinguished the difference between “food group,” “food,” and “nutrient” whereas before I had completely omitted the word “food group” and was instead using the word “nutrient” in place of the word “food.” Additionally, I now refrain from saying the word diet and instead say dietary pattern. To highlight the importance of viewing food as a whole instead of as individual nutrients, the assigned video and study by Kelly et al regarding carbohydrates and CVD mentioned that in addition to the monosaccharides and disaccharides added to foods, free sugars are also sugars naturally present in unsweetened fruit juices.2 If I was not looking at food as a whole and instead was only looking at food as “nutrients,” I would solely focus on the fact that unsweetened fruit juice contains free sugars, and that this nutrient may not be ideal for CVD patients, so therefore may think that fruit juices should be avoided by CVD patients. However, because I no longer look at foods consumed as “nutrients,” I decided to further explore what other studies suggest regarding fruit juice and CVD risk. I found a study that suggests an inverse association between 100% fruit juice and CVD incidences.3 The researchers of this particular study also highlight that the World Health Organization’s (WHO) free sugars classification fails to differentiate between added sugars and free sugars that are naturally occurring in 100% fruit juice and that this guidance from the WHO may imply that all free sugars are equally detrimental.3 Additionally, another study found that 100% fruit juice from grapes, blueberries, pomegranates, tart cherries, and cranberries may provide CVD health benefits due to containing polyphenols, flavonols, flavan-3-ols monomers, anthocyanins, in addition to several other nutrients.4 In conclusion, I now know that food is so much more than just “nutrients” and should never be referred to as such. I will forever remember that we do not eat nutrients. We eat food. References 1. Johansson U, Öhlund I, Lindberg L, et al. A randomized, controlled trial of a Nordic, protein-reduced complementary diet in infants: effects on body composition, growth, biomarkers, and dietary intake at 12 and 18 months. Am J Clin Nutr. 2023;117(6):1219-1231. doi:10.1016/j.ajcnut.2023.03.020 2. Kelly RK, Tong TYN, Watling CZ, et al. Associations between types and sources of dietary carbohydrates and cardiovascular disease risk: a prospective cohort study of UK Biobank participants. BMC Med. 2023;21(1):34. Published 2023 Feb 14. doi:10.1186/s12916-022-02712-7 3. Ruxton C, Derbyshire E, Sievenpiper J. Pure 100% fruit juices – more than just a source of free sugars? A review of the evidence of their effect on risk of cardiovascular disease, type 2 diabetes and obesity. Nutr Bull. 2021;46(4):421-424. doi: 10.1111/nbu.12526 4. Ho KKHY, Ferruzzi MG, Wightman JD. Potential health benefits of (poly)phenols derived from fruit and 100% fruit juice. Nutr Rev. 2020;78(2):145-174. doi:10.1093/nutrit/nuz041