Read the following original research article, “High Folic Acid Intake during Pregnancy Lowers Body Weight and Reduces Femoral Area and Strength in Female Rat Offspring” (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3678445/) – please pay attention to the abstract, introduction, animals and diet section of the methods, and discussion – and answer the following questions:
- Provide a one paragraph summary that highlights the purpose / objectives of the study, the study’s hypothesis, and the main results of the study.
- Why is this type of study significant in the field of nutritional sciences?
- Do you think the results of this type of study (animal research) can be applied to humans? (Please also comment on if you agree with the author’s interpretation of the applicability of this study to humans)
- Based on the results of this study, would you recommend that pregnant women stop taking folic acid supplements? Why or why not?
(Remember to provide examples to support your answers where it is appropriate (especially for Question 4): one of your references must be another original research paper – you can also use one of the studies that the article used as a reference. The other examples can be from other sources like the textbook or your own experiences)
1. Provide a one paragraph summary that highlights the purpose / objectives of the study, the study’s hypothesis, and the main results of the study.
Human adults are recommended to take 400 mcg/day from food, but pregnant mothers are usually recommended to take 400-1000 μg/day of folic acid (Mayo Clinic Staff, 2021) because the fetus needs a lot of folic acids to make the neural tube that develops into the brain and spinal cord in the early stages of pregnancy. This study aims to elucidate how excessive folic acid intake during pregnancy affects fetal phenotype and to determine its effects on offspring weight gain and bone health. Researchers gave pregnant rats a diet containing ten times the recommended intake of folic acid and experimented to see its effect on the fetus based on the hypothesis that high maternal folic acid intake would impair fetal bone health. As a result, babies of mother rats that took ten times the recommended intake of folic acid had an average of 6% lower body weight and an average of 2% smaller femur area than babies of mother rats that received the recommended intake of folic acid (Huot et al., 2013).
2. Why is this type of study significant in the field of nutritional sciences?
Although our bone mass is also influenced by lifestyle factors such as diet and physical activity, proper nutrition during pregnancy and early childhood is crucial to maintaining bone health throughout our lives and reaching peak bone mass. (Zimmerman & Snow, 2012). Adult bone health and the risk of osteoporosis are greatly influenced by whether individuals reach peak bone mass by young adulthood. Therefore, this kind of research is significant in nutrition and health sciences.
3. Do you think the results of this type of study (animal research) can be applied to humans? (Please also comment on if you agree with the author’s interpretation of the applicability of this study to humans)
Regarding the applicability of this study to humans, the author states that it may also be relevant to humans, citing multiple survey results that show that many pregnant women are taking folic acid above their permissible upper limit of 1000μ, and problematizing this situation. Folic acid's ability to support red blood cell formation and healthy cell growth and function is common in animals and humans. Therefore, I expect that the adverse effects of excessive intake of folic acid may also be common to some extent.
4. Based on the results of this study, would you recommend that pregnant women stop taking folic acid supplements? Why or why not?
No, I do not advise pregnant women to stop taking folic acid supplements.
The result that high maternal folic acid intake would impair fetal bone health was obtained by administering ten times more folic acid to a mouse, which in human case would mean that one received 2000 μg/day. However, these are pretty extreme cases, and it is rare to actually take 2000 μg/day, even taking folic acid supplements. Folate acid supplements prescribed by doctors or commercially available in Japan typically contain 400-500 μg of folic acid. Those do not exceed the RDA folic acid intake even also combined with a regular diet. One study evoluated dietary records collected from Japanese pregnant women to quantify their dietary intake of folic acid, and it shows their dietary intake of folic acid averaged 331 µg/day, and the average intake for 200 women in early pregnancy was only 294 µg/day (Kondo et al., 2011). According to this result, it is clear that diet alone can not provide the folic acid needed by pregnant women. Adequate and consistent use of these common folic acid supplements can promote continued pregnancy and healthy fetal development.
However, among the folic acid supplements on the market in Japan, the product with the highest folic acid content contains 800 μg and is sold to women who wish to become pregnant. The pharmaceutical company that sells the product is appealing to the need for high-folic acid supplements, based on the research results of many Japanese people have mutations in the methylenetetrahydrofolate reductase gene (MTHFR), so it can not be used well in our bodies even if folic acid is absorbed in the small intestine (Moriyama et al., 2002). Even considering their insistence, if we take about 400 mcg through food and then take 800 mcg through supplements, it exceeds the 1000 mcg limit set by the RDA for pregnant women, so we need to be careful with this supplement.
Huot, P. S., Dodington, D. W., Mollard, R. C., Reza-López, S. A., Sánchez-Hernández, D., Cho, C. E., Kuk, J., Ward, W. E., & Anderson, G. H. (2013). High Folic Acid Intake during Pregnancy Lowers Body Weight and Reduces Femoral Area and Strength in Female Rat Offspring. Journal of osteoporosis, 2013, 154109. Retrieved from https://doi.org/10.1155/2013/154109
Kondo, A., Asada, Y., Shibata, K., Kihira, M., Ninomiya, K., Suzuki, M., Oguchi, H., Hayashi, Y., Narita, O., Watanabe, J., & Shimosuka, Y. (2011). Dietary folate intakes and effects of folic acid supplementation on folate concentrations among Japanese pregnant women. The journal of obstetrics and gynaecology research, 37(4), 331-336. Retrieved from https://doi.org/10.1111/j.1447-0756.2010.01358.x
Mayo Clinic Staff. (2021). Folate (folic acid). Mayo Clinic. Retrieved from https://www.mayoclinic.org/drugs-supplements-folate/art-20364625
Moriyama, Y., Okamura, T., Kajinami, K., Iso, H., Inazu, A., Kawashiri, M., Mizuno, M., Takeda, Y., Sakamoto, Y., Kimura, H., Suzuki, H., & Mabuchi, H. (2002). Effects of serum B vitamins on elevated plasma homocysteine levels associated with the mutation of methylenetetrahydrofolate reductase gene in Japanese. Atherosclerosis, 164(2), 321-328. Retrieved from https://doi.org/10.1016/s0021-9150(02)00105-3
Zimmerman, M., & Snow, B. (2012). 2.4 National Goals for Nutrition and Health: Healthy People 2020. In An Introduction to Nutrition, V1.0. Unnamed Publisher. Retrieved from https://2012books.lardbucket.org/books/an-introduction-to-nutrition/s05-06-a-fresh-perspective-sustainabl.html
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