Nutrition

Embryology - 25 Apr 2024        Expand to Translate
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Educational Use Only - Embryology is an educational resource for learning concepts in embryological development, no clinical information is provided and content should not be used for any other purpose.

Introduction

Folate Fruits

This current page is a start page for your exploration of topics related to nutrition and development.

While there are many sites and information available concerning postnatal nutrition, prenatally research has mainly focussed on developmental effects of specific deficiencies (folate and iodine) and the teratogenic effects of retinoic acid.

See also the National Health and Medical Research Council (NHMRC) publication NHMRC - Nutrient Reference Values for Australia and New Zealand Including Recommended Dietary Intakes. "The Nutrient Reference Values outline the levels of intake of essential nutrients considered to be adequate to meet the known nutritional needs of practically all healthy people for prevention of deficiency states. The document can be used by health professionals to assess the likelihood of inadequate intake in individuals or groups of people." Some text on this current page is modified from this report.

In Australia and New Zealand

Before mandatory folic acid fortification was introduced:

• mean dietary folic acid intakes for women aged 16–44 years (the target population) in Australia was 108 micrograms (μg) of folic acid per day and in New Zealand was 62 μg of folic acid per day, well below the recommended 400 μg per day.
• there were 149 pregnancies affected by NTDs in 2005 in Australia (rate of 13.3 per 10,000 births) in the three states that provide the most accurate baseline of NTD incidence (South Australia, Western Australia and Victoria), and 63 pregnancies affected by NTDs in 2003 in New Zealand (rate of 11.2 per 10,000 births).

Before mandatory iodine fortification was introduced:

• large proportions of the Australian and New Zealand population had inadequate iodine intakes.
• national surveys measuring median urinary iodine concentration (MUIC) in schoolchildren, an indicator of overall population status, confirmed mild iodine deficiency in both countries.
  • the concentration was 96 μg per litre in Australia, and 66 μg per litre in New Zealand, less than the 100–200 μg per litre considered optimal.

The Nobel Prize in Chemistry 1937 Walter Norman Haworth "for his investigations on carbohydrates and vitamin C" and Paul Karrer "for his investigations on carotenoids, flavins and vitamins A and B2".

Some Recent Findings

Vitamin D - Maternal BMI Associations with Maternal and Cord Blood Vitamin D Levels in a North American Subset of Hyperglycemia and Adverse Pregnancy Outcome (HAPO) Study Participants "Obesity in pregnancy may be associated with reduced placental transfer of 25-hydroxyvitamin D (25-OHD). The objective of this study was to examine associations between maternal BMI and maternal and cord blood levels of 25-OHD in full term neonates born to a single racial cohort residing at similar latitude. Secondary objectives were to examine associations between maternal glucose tolerance with maternal levels of 25-OHD and the relationship between cord blood 25-OHD levels and neonatal size. With adjustment for maternal age, field center, birth season and maternal serum 25-OHD, the association of cord blood 25-OHD with maternal BMI was attenuated. Neither birth weight nor neonatal adiposity was significantly associated with cord blood 25-OHD levels. CONCLUSION: These results suggest that maternal levels of 25-OHD are associated with maternal BMI. The results also suggest that interpretation of neonatal 25-OHD levels may need to incorporate specific maternal factors in addition to season of birth and latitude." Protein - Maternal Diabetes Leads to Adaptation in Embryonic Amino Acid Metabolism during Early Pregnancy "During pregnancy an adequate amino acid supply is essential for embryo development and fetal growth. We have studied amino acid composition and branched chain amino acid (BCAA) metabolism at day 6 p.c. in diabetic rabbits and blastocysts. In the plasma of diabetic rabbits the concentrations of 12 amino acids were altered in comparison to the controls. Notably, the concentrations of the BCAA leucine, isoleucine and valine were approximately three-fold higher in diabetic rabbits than in the control. ... These results demonstrate a direct impact of maternal diabetes on BCAA concentrations and degradation in mammalian blastocysts with influence on embryonic mTOR signalling." Maternal Diabetes | Rabbit Development Vitamin C - Depletion in Prenatal Guinea Pigs as a Model of Lissencephaly Type II "Humans and guinea pigs are unable to produce vitamin C, with deficiency resulting in a well-known disorder of collagen synthesis. Pial basement membrane structure preservation is essential in the proper migration of neurons. In our study, intrauterine deprivation of vitamin C in guinea pig fetuses led to a collagen synthesis disorder, weakness, and finally a breach of pial basement membrane. ...The most severe form of dysplastic changes was characterized by marked irregularity of the cerebellar cortex similar to that in lissencephaly type II. Thus, prenatal vitamin C deficiency represents a novel animal model to study the effects of collagen synthesis on development of breaches in the pial basement membrane, disordered migration of neurons, dysplasia of cerebellar cortex, and the pathogenesis of lissencephaly." Cerebellum Development Vitamin K CDC finds cluster of newborns in Tennessee with bleeding disorder Report highlights importance of vitamin K shot at birth. "The Centers for Disease Control and Prevention has identified a cluster of newborns in Tennessee with late vitamin K deficiency bleeding (VKDB). VKDB is a serious, but preventable bleeding disorder that can cause bleeding in the brain. In each case, the newborn’s parents declined vitamin K injection at birth, mainly because they were unaware of the health benefits of vitamin K at birth." (More? American Academy of Pediatrics Report Of Committee On Nutrition - Vitamin K Compounds And The Water-Soluble Analogues (1961) Vitamin A and E status in very low birth weight infants "High prevalence of vitamin A and vitamin E deficiency was found in VLBW infants starting from birth to term postmenstrual age."

More recent papers

This table allows an automated computer search of the external PubMed database using the listed "Search term" text link. This search now requires a manual link as the original PubMed extension has been disabled. The displayed list of references do not reflect any editorial selection of material based on content or relevance. References also appear on this list based upon the date of the actual page viewing. References listed on the rest of the content page and the associated discussion page (listed under the publication year sub-headings) do include some editorial selection based upon both relevance and availability. More? References | Discussion Page | Journal Searches | 2019 References | 2020 References Search term: Fetal Nutrition <pubmed limit=5>Fetal Nutrition</pubmed>

Folic Acid

In 2001, the Australian estimated birth prevalence of neural tube defects was 0.5 per 1,000 births (National Perinatal Statistics Unit). Low maternal dietary folic acid (folate) has been shown to be associated with the development of neural tube defects.

In the U.S.A. the Food and Drug Administration in 1996 authorized that all enriched cereal grain products be fortified with folic acid, with optional fortification beginning in March 1996 and mandatory fortification in January 1998.

Links: Folic Acid and Neural Tube Defects

Iodine

Thyroxine (T4) molecular structure showing iodine positions (red rings)

"Iodine is an essential nutrient that humans need in very small quantities. The thyroid uses iodine to produce hormones vital to ensure normal development of the brain and nervous system before birth, in babies and young children. For this reason, it is very important that pregnant and breastfeeding women get enough iodine. The National Health and Medical Research Council recommends that all women who are pregnant, breastfeeding or considering pregnancy, take an iodine supplement of 150 micrograms (μg) each day. Women with pre-existing thyroid conditions should seek advice from their medical practitioner prior to taking a supplement." Text from

Links: Iodine Deficiency | Iodine supplementation for Pregnant and Breastfeeding Women NHMRC - Nutrition & Diet Publications

Vitamins

Vitamin A

Retinoic acid is a metabolite of vitamin A (retinol) and may affect prenatal development. Postnatal dietary supplementation of children is recommended when diet may be inadequate. Vitamin A is required for many systems including: visual system, cell function for growth, epithelial integrity, red blood cell production, immunity, and reproduction.

The following text is from a recent review of published data.

What is already known on this topic

• Vitamin A is an essential nutrient; it must be obtained through diet
• In low and middle income countries, many people (especially children) do not eat enough vitamin A
• Vitamin A deficiency is related to vision problems and increased susceptibility to infectious disease and death
• WHO recommends vitamin A supplements for children, pregnant women, and breastfeeding mothers

What this study adds

• There have been 43 trials of vitamin A for children aged 6 months to 5 years old, including about 215,633 children
• In low and middle income countries, vitamin A supplementation is associated with a 24% reduction in mortality
• Vitamin A supplementation might reduce mortality by preventing measles and diarrhoea; it also prevents blindness
• The evidence for vitamin A is compelling and clear; further trials comparing vitamin A with placebo would be unethical

• Spermatozoa Development - "Retinoic acid appears to act in a pulsatile manner, periodically driving spermatogonial differentiation and meiotic onset at discrete points along testis tubules, and as a result, is likely to be responsible for generating and maintaining the cycle of the seminiferous epithelium."

Links: Developmental Signals - Retinoic acid | Spermatozoa Development | Cell Division - Meiosis

Vitamin B

Eight separate water-soluble vitamins that play important roles in cell metabolism. Folic acid or vitamin B₉ (folacin) and folate (naturally occurring form) are an important dietary requirement for normal neural development. Low levels have been show associated with neural tube defects including spina bifida.

Links: Neural System Development | Neural System - Abnormalities

Vitamin C

Ascorbic acid (vitamin C) is necessary for the formation of collagen, reducing free radicals, and aiding in iron absorption. Scurvy is a disease of dietary ascorbic acid deficiency that is very uncommon today, except in economically disadvantaged populations with poor nutrition. Occurance in children is very rare and can lead to musculoskeletal abnormalities, and has also been seen in neurologic illness.

Vitamin D

Vitamin D3

Vitamin D₃ is produced in the skin from 7-dehydrocholesterol in a photoreaction induced by ultraviolet B (UVB) radiation from the sun. This is then released into circulation where it is hydroxylated in the liver and kidney to a more active form. Circulating 25-hydroxyvitamin D3 (25[OH]D), the most commonly used index of vitamin D status, is converted to the active hormone 1,25 dihydroxyvitamin D3 (1,25[OH]2D), which, operating through the vitamin D receptor (VDR). The vitamin D receptor belongs to the nuclear receptor superfamily.

Tissue	Substrate	Product
Integument	7-dehydrocholesterol	Vitamin D3
Liver	Vitamin D3	25-hydroxyvitamin D3 (calcidiol)
Kidney	25-hydroxyvitamin D3	1,25-dihydroxyvitamin D3 (calcitriol, 1α,25-dihydroxyvitamin D)

In the skin Vitamin D₃ regulates both epidermal proliferation and differentiation. As a circulating hormone, it regulates calcium levels in the blood, required for bone and muscle development.

USA Institute of Medicine expert committee "calcium requirements varied with age, from 700 mg a day for children aged 1-3 years up to 1200 mg a day for women aged 51 to 70 and 1300 mg a day for teenagers and pregnant and lactating women."

• Australia - Newborn-serum 25OHD concentrations depend on the maternal circulating plasma 25OHD level at least during the third trimester. Neonatal 25OHD levels obtained by EIA correlated well with liquid chromatography/tandem mass spectrometry (LC-MSMS). Although the EIA values for neonates were greater than LC-MSMS values, this difference was not statistically significant.
• UK - Avoidance of vitamin D deficiency in pregnancy in the United Kingdom: the case for a unified approach in National policy.
• USA 2004 - Vitamin D requirements during pregnancy.

The vitamin D receptor (VDR) is found on most non-skeletal human cells that may indicate a role in more than the bone and calcium metabolism.

• respiratory tract is a consequence of its activity in the immune system.
• vitamin D deficiency occurs with gastrointestinal diseases such as inflammatory bowel disease, coeliac disease, liver, pancreas or cardiac diseases.
• links to diabetes. VDR and 1α-hydroxylase have been detected in the cutaneous capillary vessels, endothelium, vascular smooth muscles, myocytes and cardiac fibroblasts.

Kidney Endocrine
Hormone	Function	Comment
Renin	increase angiotensin-aldosterone system	paracrine, renin is released by juxtaglomerular cells
Prostaglandins	decrease sodium (Na+) reabsorption	paracrine, (PGE2) vasodilator regulate renal vascular reactivity
Erythropoietin	increase Erythrocyte production	endocrine, promotes red blood cell formation in bone marrow
1,25 (OH)2 vitamin D	Calcium homeostasis	endocrine, biologically active form of vitamin D
Prekallikreins	increase Kinin production	paracrine, act locally to induce vasodilation and contraction of smooth muscle

Links: Vitamin D3 | Vitamin D3 synthesis | Integumentary | Nutrition | Endocrine Kidney | Parathyroid

External Links: Dietary Reference Intakes for Calcium and Vitamin D | Paediatric Endocrine Group; Paediatric Bone Australasia. Prevention and treatment of infant and childhood vitamin D deficiency in Australia and New Zealand: a consensus statement. 2006 PMID16948623 | Vitamin D - a review 2008 PMID19142273 | AFP)

Vitamin E

Vitamin E has a role in immunity and cell function (controls free radicals mediated disturbances and maintains membrane integrity). Animal studies suggest a protective role for asthma risk.

Tocotrienols are natural compounds acting as dietary members of the vitamin E family. They are found in a number of vegetable oils, wheat germ, barley, and certain types of nuts and grains.

Vitamin K

A generic term for derivatives of 2-methyl-1,4-naphthoquinone that have coagulation activity. Daily requirement for vitamin K is about 1 µg/kg. In newborns vitamin K nutrition is at risk.

• Required for synthesis of prothrombin and proconvertin (stable factor, factor VII).
• May also be involved in synthesis of Stuart-Prower factor (factor X) and PTC (plasma thromboplastic factor, factor IX) since clotting defects due to deficiencies of these factors as well as to deficiencies of prothrombin and proconvertin occur in states of vitamin K deficiency.
• CDC finds cluster of newborns in Tennessee with bleeding disorder Report highlights importance of vitamin K shot at birth.

Links: American Academy of Pediatrics Report Of Committee On Nutrition - Vitamin K Compounds And The Water-Soluble Analogues (1961)

Iron

Heme b

Maternal iron (Fe) deficiency can be a common disorder during pregnancy and also in the postnatal period for neonatal neural development. Haemoglobin is the iron-containing oxygen-transport metalloprotein located in maternal and fetal red blood cells and myoglobin is the equivalent protein located in muscle. Iron is also required in some cellular enzymatic processes as a cofactor.

During pregnancy the maternal blood volume increases and the packed cell volume and haemoglobin (Hb) concentration can fall, a condition is known as "anaemia of pregnancy" (haemoglobin value below 11 g/dL). Therefore an increase of about 50% above the recommended daily dietary intake of Fe is suggested during pregnancy. Preventive treatment can include prophylaxis iron supplements and food fortification with iron.

Fetal demands for iron are maximal during the third trimester. Prenatal maternal use of iron can also improve birth weight, in a linear dose-response fashion, perhaps reducing the risk of low birth weight.

Similar micronutrient requirements have been identified for other trace metals such as copper (Cu), see the review.

Links: WHO Micronutrient deficiencies | WHO Anaemia database

Protein

There are normally 20 amino acids found in proteins, some of which can be made by the body while nine are essential (unable to synthesise from simpler molecules) in the diet. Modified amino acids are the basis of several hormones, such as noradrenaline (norepinepherine), adrenalin (epinepherine) and thyroid hormone. (More? Endocrine System Development)

Essential amino acids

• histidine
• isoleucine
• leucine
• lysine
• methionine
• phenylalanine
• threonine
• tryptophan
• valine

Cysteine and tyrosine can partly replace methionine and phenylalanine.

Fats

• Fats are the highest form of energy for the body.
• Aid in the absorption of the fat-soluble vitamins (A, D, E and K) and other fat-soluble biologically-active components.
• Three major types of naturally-occurring fatty acids:
  • saturated - mainly in animal-based foods. For example, found in milk, cream, butter and cheese, land animal meats.
  • cis-monounsaturated - mainly in plant-based foods. For example, oleic acid found in olive, canola and peanut oils.
  • cis-polyunsaturated - mainly in plant-based foods. For example, linoleic acid found in seed oils, eg sunflower, safflower and corn.
• trans fatty acids are produced by partial hydrogenation of polyunsaturated oils in food processing and also occur in ruminant animal foods.

Carbohydrates

• Dietary carbohydrate provides energy to specific tissues, for example the brain requires glucose.
  • Note, infant's brain is large relative to body size and uses 60% of the infant’s total energy intake.

Fibre

• Dietary fibre is essential for proper gut function
• Related also to risk reduction for some chronic diseases (heart disease, certain cancers and diabetes).

Water

• Water is essential because it is required in quantities above the body’s production.
• Water loss from lungs and skin are responsible for 50% of total water turnover.

References

Reviews

<pubmed>26451605</pubmed> <pubmed>21291560</pubmed>

Articles

<pubmed>23163681</pubmed> <pubmed>20629350</pubmed>

Books

• Institute of Medicine (US) Panel on Micronutrients. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. Washington (DC): National Academies Press (US); 2001. Available from: http://www.ncbi.nlm.nih.gov/books/NBK222310/

Terms

• Adequate Intake - (AI) The average daily nutrient intake level based on observed or experimentally-determined approximations or estimates of nutrient intake by a group (or groups) of apparently healthy people that are assumed to be adequate. Used when an RDI cannot be determined.
• Estimated Average Requirement - (EAR) A daily nutrient level estimated to meet the requirements of half the healthy individuals in a particular life stage and gender group.
• Median Urinary Iodine Concentration - (MUIC) Urinary iodine concentration is the prime indicator of nutritional iodine status and is used to evaluate population-based iodine supplementation. The median value is determined from a population sample.
• Recommended Dietary Intake - (RDI) The average daily dietary intake level that is sufficient to meet the nutrient requirements of nearly all (97–98 per cent) healthy individuals in a particular life stage and gender group.
• Upper Level of Intake - (UL) The highest average daily nutrient intake level likely to pose no adverse health effects to almost all individuals in the general population. As intake increases above the UL, the potential risk of adverse effects increases.
• Urinary Iodine Concentration - (UIC)

Some terms from NHMRC publication, adapted from Food and Nutrition Board: Institute of Medicine (USA and Canada).

External Links

External Links Notice - The dynamic nature of the internet may mean that some of these listed links may no longer function. If the link no longer works search the web with the link text or name. Links to any external commercial sites are provided for information purposes only and should never be considered an endorsement. UNSW Embryology is provided as an educational resource with no clinical information or commercial affiliation.

• World Health Organization (WHO)
  • Vitamin and Mineral Nutrition Information System (VMNIS)
  • WHO Micronutrient deficiencies
  • WHO Anaemia database
  • Guidelines for the use of iron supplements to prevent and treat iron deficiency anemia
• USA NIH
  • Biomarkers of Nutrition for Development (BOND) Program
  • http://www.nutrition.gov/ | Life Stages - Women Pregnancy | Life Stages - Infants
• Medline Plus Infant and Newborn Nutrition
• Australia NHMRC
  • Nutrition & Diet Publications
  • NHMRC - Nutrient Reference Values for Australia and New Zealand Including Recommended Dietary Intakes 2006 | PDF Executive Summary

Glossary Links

Glossary: A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | Numbers | Symbols | Term Link

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Cite this page: Hill, M.A. (2024, April 25) Embryology Nutrition. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Nutrition

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© Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G