Micronutrient Deficiencies Flashcards
Cultivars
Vegetables and fruits may have lower mineral and vitamin content due to bigger plants, higher dilution factors, cultivated quickly so not absorbing enough nutrients.
Selective breeding has reduced butter/ sour crops which are high in phytonutrients
High CO2 due to climate change has made less nutritious crops
Iron functions
Assists in transport and storage of oxygen
ATP cofactor for cytochromes in mitochondria
Assists in immunity
Assists in synthesis of neurotransmitters dopamine and serotonin
Haem iron and absorption
Animal foods 60% haem, 40% non haem
Haem 25% absorbed- non haem 6% absorbed
Haem need HCL to release haem Fe from protein
Absorption of non haem iron/ minerals and Chelators. Chelators shield the charge of the mineral so that it’s not held by fur lining and can be absorbed. Gut lining is negatively changed and minerals are positively charged.
Non haem iron and absorption
Found in plant foods
Needs HCl/ pepsin to solubilise, hydrolyse and convert Fe3 to Fe2
Blocked by Ca and phytates, so better to eat leafy greens cooked
Vit C chelates Fe, therefore soluble and passes to transferring, hence better absorption
Vit A increases absorption, releases stores Fe from liver- or maybe not producing enough beta carotene to produce Vit A
Phytates and coffee
Phytates
Binds non haem iron and many other minerals
Grains, legumes and nuts
Reduced by sprouting, soaking, fermenting, leavening, roasting and cooking
Caffeine in coffee, tea
Decreases non haem Fe absorption
Should drink between meals
Fe blood tests
Ferritin
25% of total body iron is present as storage iron. Ferritin in bone marrow, rest in liver, spleen and muscles.
Transferrin and transferrin saturation
Main Fe transport protein (Vit C) satiration refers to how saturated it is with age
TIBC
Total iron building capacity (measure all proteins that bind Fe)
Serum Fe
Not useful due to high fluctuation
Low ferritin and increased TIBC means iron stores are low and body adapts by increasing TIBC- iron deficiency anaemia
High ferritin and decreased TIBC means stores are increasing and circulating iron is decreasing (due to hormone hepcidin) to prevent bacteria from feeding on this- anaemia of chronic disease
Symptoms of low iron
Fatigue, cold extremities
Impaired memory and mental function, headache constipation
Shortness of breath, heart palpitations, restless legs, changes in nail structure
Pale skin, face, nail beds
Tongue smooth and pale
Selenium
Energy T3 synthesis/ breakdown Protects cell membranes, ageing skin, CHD, cancer Immunity Sperm production Absorption needs stomach acid
Signs:
Muscle pain, macrocytic anaemia, >aging skin,
Deficiency not prevalent in Aus.
T4:T3 (ideal 3:1 or 15:5), serum/ plasma Se.
Zinc
Forms part of 100 enzymes for metabolism of protein/ carbs/ fats
Assists in synthesis of omega 3, cholesterol, DNA, B6, Vit A mobilisation
Assist neurotransmitter dopamine, GABA, serotonin, melatonin
Assist hormones oestrogen, corticosteroids, thyroxine, insulin and glucagon
Zinc lost in intestinal secretions, urine, skin and semen. Patients with eczema at increased risk.
Symptoms of zinc deficiency
Decreased growth in children Decreased appetite Mental fatigue Aggression and anxiety Decreased sleep Decreased wound healing Decreased immunity and gut function Decreased sperm count
Zinc tests
Plasma Zn
RBC or WBC
Liquid zinc taste test? Subjective and inaccurate
Thyroid system
Need iodine to make T4
T4 inactive - Se, Zn, B2 Vit D, insulinc progesterone help activate T3
Hyperthyroid - low TSH <0.4
Autoimmune such as graves, goitre, coelia.
Or high iodine
Hypothyroid high TSH >4.5 low T4 low T3
Autoimmune- coeliac
Low iodine, Se, iron
Weight gain- constipation
GERD
Iodine
Production of thyroxine (T4/T3) Metabolic rate Glucose, lipids, nutrients Heart Brain, nerves myelination Stomach acid for gut function
Urinary iodine test
High TSH low T4 mah be sign of low iodine
Selenium
High T4 low T3 may be sign of low Se (ideal 3:1)
Serum selenium
Need to balance with iodine for hormone production
