9b. Minerals - Micro Flashcards
Which metalloenzyme functions is Zn a cofactor in?
Superoxide dismutase (SOD) - AO Alcohol dehydrogenase - breakdown of alcohol Carboxypeptidase - digestion of proteins Haem synthesis Folate absorption DNA/RNA synthesis
Food sources of Zn
Oysters Adzuki beans Rye flour Sesame seeds Calf's liver
What are the functions of Zn?
Reproduction Endocrine Digestion Immunity Sensory Cell proliferation
What are the functions of Zn in reproduction?
Production of sex hormones
Spermatogenesis
Inhibits 5a-reductase
(e.g. inhibits conversion of testosterone to more potent androgen DHT)
What are the functions of Zn in endocrine?
T4 to T3 conversion
What are the functions of Zn in digestion?
Production of HCl
Creation of pancreatic enzymes
What are the functions of Zn in immunity?
AO
Increases T and B cell activity
Anti-inflammatory
Anti-viral
What are the functions of Zn in sensory?
Taste and smell
Supports vision and hearing
What are the functions of Zn in cell proliferation?
Cell proliferation/differentiation e.g. skin
Gene expression
Aids tight junctions
What are the therapeutic uses of Zn in reproduction?
Low testosterone
Infertility
Erectile dysfunction
What are the therapeutic uses of Zn in endocrine?
Thyroid health
What are the therapeutic uses of Zn in digestion?
Weak digestion
Hypochlorhydria
What are the therapeutic uses of Zn in immunity?
Frequent infections
Inflammation
CV disease
What are the functions of Zn in sensory?
Poor taste/smell/vision
Tinnitus
What are the functions of Zn in cell proliferation?
Acne
Wound healing
Burns
Cancer
What percentage of Zn is absorbed by the body?
20-40%
What can enhance the absorption of Zn?
Protein
What can inhibit the absorption of Zn?
Phytates
Excess Ca, Cu, Fe
Food sources highest in phytates
Wholegrains
Legumes
Nuts
Seeds
How can phytate levels be reduced?
Soaking
Sprouting
Fermenting
What can Zn supplementation inhibit?
Cu absorption
What can cause Zn deficiency?
Malabsorption
Diet high in phytates
Diet low in Zn rich foods
Which groups are at risk of Zn deficiency?
Older adults
Alcoholics
Pregnant women
Athletes
Signs/symptoms of Zn deficiency
Poor sense of taste/smell Recurrent infections Delayed wound healing Skin disorders e.g. acne Infertility Weak digestion
Which forms of Zn supplements are best absorbed?
Citrate
Acetate
Glycinate
What can long-term Zn supplementation lead to?
Cu deficiency
What are the two forms of Fe present in the body?
Ferrous - Fe2+
Ferric - Fe3+
Which form of Fe is needed for absorption?
Ferrous
Where can we mostly find Fe?
Blood
Bone marrow
Muscles
Enzymes
From what food sources can we find non-haem iron?
Plants
Animals
Which form of Fe is non-haem iron?
Ferritic
From what food sources can haem iron be found?
Animals
Fish
Which form of Fe is haem iron?
Ferrous
Examples of Fe food sources
Meat Fish Pumpkin seeds Sesame seeds Quinoa Soy beans Spinach Dried apricots
What are the functions of Fe?
Oxygen transport and storage Energy Endocrine Immune Neurotransmitter synthesis
What are the functions of Fe in oxygen transport and storage?
A component of haemoglobin (O2 stores in blood)
A component of myoglobin (O2 stores in muscles)
What are the functions of Fe in energy production?
Enzyme cofactor in electron transport chain
What are the functions of Fe in endocrine?
Cofactor for the enzyme thyroid peroxidase (needed to synthesis thyroid hormones)
What are the functions of Fe in immunity?
Lymphocyte proliferation and maturation
What is the function of Fe in neurotransmitter synthesis?
Cofactor for tyrosine hydroxylase
converts tyrosine to dopamine
What are the therapeutic uses of Fe in oxygen storage and transport?
Anaemia
Fatigue
Muscle weakness
Exercise - endurance
What are the therapeutic uses of Fe in energy production?
Fatigue
Mitochondrial support
What are the therapeutic uses of Fe in endocrine?
Hypothyroidism
What are the therapeutic uses of Fe in immunity?
Immune support
What are the therapeutic uses of Fe in neurotransmitter synthesis?
Cognition/learning
Parkinson’s
Where is Fe not used for haemoglobin production stored?
In the protein ferritin
What happens to Fe when Fe stores are high?
Liver converts ferritin to hemosiderin which releases Fe more slowly
Once a RBC has come to the end of its lifespan what happens?
Spleen and liver dismantle it, salvage the Fe and recycle it to make more erythrocytes
Where does the body lose some Fe on a daily basis?
Via GI tract
When bleeding occurs
Is Fe excreted from the body?
No
How are Fe levels regulated?
By the amount absorbed in the intestine
higher levels in tissues = down regulation of gut absorption
What helps the body absorb Fe from food?
Proteins
What does mucosal ferritin do?
Receives Fe from food and stores it in the SI mucosal cells
What does mucosal transferrin do?
Transfers the Fe from SI mucosal cells to blood transferrin which transports the iron to the rest of the body
What happens if the body doesn’t need Fe?
It’s carried out when the intestinal cells are shed and excreted via faeces
(every 3 days)
What does Fe absorption depend on?
GI tract health
Presence of supporting/inhibiting nutrients e.g. vit C/phytates
Food source (haem vs non-haem)
What is the absorption rate of haem iron?
15-35%
What is the absorption rate of non-haem iron?
2-20%
Is haem or non-haem iron absorption more sensitive to body iron stores?
Non-haem
Why are supplement doses of Fe typically high?
Fe from supplements is less well absorbed than from food
How can non-haem Fe absorption be enhanced?
Vit C with every meal
Build meals around Fe-rich foods
Avoid drinking caffeine and dairy at meal times
Eat foods that contain yeast
Eat sprouted/fermented foods to reduce inhibitors like phytates
Eliminate junk food
How does vit C enhance non-haem Fe absorption?
A vit C dependent enzyme called vit C ferrireductase is embedded in the cell membranes of duodenal enterocytes that converts Fe from the Fe+3 to Fe+2 state
What can inhibit the absorption of non-haem iron?
Phytates Oxalates Polyphenols Calcium Tannins
Which life stages are vulnerable to iron deficiency?
Women of reproductive age
Pregnancy (increased blood volume)
Times of rapid growth (teenagers, young kids)
What are the symptoms of Fe deficieny anaemia?
Fatigue on exertion Weakness Headaches Apathy Breathlessness Poor resistance to cold temperatures
What are the signs of Fe deficiency anaemia?
Pallor
Nail spooning
Hair loss
Tachycardia
Why is Fe toxicity a risk?
Because there’s no physiological mechanism for excretion
Haem Fe is more efficiently absorbed and the body has less control over how much it absorbs
(unlike non-haem iron)
Why can Fe overload be harmful?
Free Fe is a pro-oxidant and can cause oxidative damage
(associated with atherosclerosis, cancer, AZD)
Fe is a bacterial growth factor and can cause increased infection rates
Excess Fe can accumulate in organs e.g. brain, liver
What can contribute to Fe overload?
Haemochromatosis (genetic disorder that enhances Fe absorption)
Indiscriminate use of Fe supplements
High dose vit C supplementation
Excessive red meat consumption
Which nutrients can enhance the absorption of Fe?
Vit C
Which nutrients inhibit the absorption of Fe?
Zn
Cu
Ca
Which amino acids can selenium be found bound to?
Cysteine
Methionine
Where does Se mainly function?
Cytosol
Mitochondria
Main food sources of Se
Brazil nuts Yellowfin tuna Durum wheat Calf's liver Garlic
What are the functions of Se?
Thyroid hormones
Antioxidant
Immunity
Reproduction
What are the functions of Se in thyroid production?
Conversion of thyroxine (T4) to triiodothyronine (T3)
What are the functions of Se an AO?
Cofactor in glutathione peroxidase
enzyme that protects cells from free radical damage
What can the active site of glutathione peroxidase be occupied by?
Mercury
What are the functions of Se in immunity?
T cell proliferation and activity
Antibody production
What are the functions of Se in reproduction?
Sperm motility
What are the therapeutic uses of Se in thyroid hormones?
Hypothyroidism
Energy metabolism
What are the therapeutic uses of Se in AO?
Cell AO protection
Heavy metal detox
Acne
What are the therapeutic uses of Se in immunity?
Viral prevention
Recovery from colds
Anti cancer
What are the therapeutic uses of Se in reproduction?
Male fertility
Where is Se mostly absorbed?
Duodenum
When is absorption of Se more efficient?
Under conditions of deficiency
Which type of food source is Se more bioavailable?
Plant sources
What manages Se homeostasis?
Kidneys
How is excess Se excreted?
In urine
What can decrease Se levels?
Inflammation
What is a functional marker of Se deficiency?
Elevated T4 and lowered T3
What is Keshan disease?
Endemic cardiomyopathy that affects children in China where soil is known to be Se deficient
What are the signs and symptoms of Se deficiency?
Cardiomyopathy Infertility Muscle pain Weakness Elevated liver enzymes Growth retardation
What is important for the detoxification of Se?
Efficient methylation
What are the symptoms of Se toxicity?
Brittle hair/nails Skin lesions Dermatitis Depression Garlic odour
What is the TUL for Se?
300ug/day
How do I and Se interact?
In severe I deficiency, Se supplementation can trigger/exacerbate hypothyroidism by accelerating T4 metabolism
How do Zn, Cu and Se interact?
Supplementing with Zn/Cu may increase Se requirements
How do Se and vit E interact?
Se deficiency aggravates the effects of vit E deficiency
How do Se and PUFAs interact?
Ingestion of large amounts of DHA and EPA increases the requirement for Se
Which group of enzymes is Cu a component of?
Cuproenzymes
Where is Cu mostly absorbed?
SI
Where is Cu excreted?
In bile
Food sources of Cu
Calf's liver Sesame seeds Shiitake mushrooms Quinoa Oysters
What are the functions of Cu?
Red blood cells Antioxidant Immunity Structure Nervous system
What are the functions of Cu in red blood cells?
Haem synthesis (with Fe) Formation of erythrocytes
What are the functions of Cu as an antioxidant?
Component of AO enzymes superoxide dismutase and ceruloplasmin
What are the functions of Cu in immunity?
Killing of bacteria by phagocytes
What are the functions of Cu in structure?
Supports the structure of skin, blood vessels and bone
Component of lysyl oxidase - enzyme needed for cross-linking collagen and elastin
Melatonin formation
What are the functions of Cu in the nervous system?
Formation and maintenance of the myelin sheath
Cofactor for conversion of dopamine to noradrenaline
What are the therapeutic uses of Cu in red blood cells?
Anaemia
Fatigue
What are the therapeutic uses of Cu as an AO?
Free radical protection
Atherosclerosis
What are the therapeutic uses of Cu in immunity?
Neutropenia
Infections
What are the therapeutic uses of Cu in structure?
Wound healing
Burns
Vascular health
Osteoporosis
What are the therapeutic uses of Cu in the nervous system?
Neurotransmitter synthesis
Alertness
Focus
Fight or flight
What can induce Cu deficiency?
Long-term Zn supplementation
Infants fed cow’s milk
What are the common signs and symptoms of Cu deficiency?
Anaemia Bone fractures Impaired growth Reduced skin pigmentation Recurrent infections
What can cause acute toxicity of Cu?
Contaminated drinking water (from old copper pipes)
Genetic disorders
What are the symptoms of acute Cu toxicity?
Vomiting Diarrhoea Liver/kidney damage Haemolytic anaemia Coma Death
What can cause copper overload?
Oestrogen (in women)
What are the symptoms of Cu overload?
Emotional instability ADHD Intolerance to OCP Low immunity Skin sensitivity to cheap metal Allergies Acne
If someone presents with possible Cu overload, what is the best route to explore?
Zn deficiency
Gut function
How much of dietary iodine is absorbed?
100%
Where is the main source of I?
Ocean
Food sources of I?
Sea vegetables
Ocean fish
Shellfish
Eggs/dairy due to fortification of animal feed
What are the functions of I?
Thyroid hormones
Brain health
Metabolism
What are the functions of I in thyroid hormones?
Essential component (T4 = 4 iodine atoms; T3 = 3 iodine atoms)
What are the functions of I in brain health?
Foetal and infant development
What are the functions of I in metabolism?
Critical determinants of energy metabolism in cells
What are the therapeutic uses of I in thyroid hormones?
Hypothyroidism
What are the therapeutic uses of I in brain health?
Cognitive function during childhood
What are the therapeutic uses of I in metabolism?
Reversing slow metabolism
How are thyroid hormones made?
Thyroid gland traps iodine from blood
Iodine and tyrosine are bound to thyroglobulin
Se-dependent enzyme, iodothyronine deiodinase, converts inactive T4 to active T3
Rate of capture is determined by TSH
How was I deficiency addressed in 20th century?
Table salt iodised
Cattle feed iodine fortified
What can I deficiency lead to?
Hypothyroidism
Can hypothyroidism occur without an I deficiency?
Yes - Hashimoto’s Thyroiditis
What can severe I deficiency during pregnancy cause?
Extreme and irreversible mental and physical retardation
What is the TUL for I?
600mcg
Which nutrients, as well as I, may also be suboptimal in hypothyroidism?
Se
Zn
Fe
Cu
Which nutrients are crucial to I utilisation?
Tyrosine
Zn
Mg
B vits
Which foods may interfere with I uptake?
Goitrogenic foods - soya, millet, raw brassica veg
What percentage of Mn is absorbed?
1-5%
Where is Mn mostly absorbed?
Intestines
Where is Mn mostly stored?
Bone
Metabolically active organs - liver, kidneys, pancreas, brain
Food sources of Mn
Cloves
Hazelnuts
Wheat germ
Blue mussels
What are the functions of Mn?
Structural
Antioxidant
Metabolism
What are the structural functions of Mn?
Cofactor needed for synthesis of proteoglycans (e.g. in cartilage)
Activates enzyme needed for collagen formation
What are the AO functions of Mn?
Cofactor for the AO Mn superoxide dismutase (MnSOD)
What are the metabolic functions of Mn?
Mn-activated enzymes facilitate the metabolism of carbs, amino acids and cholesterol
What are the therapeutic uses of Mn in structure?
Healthy cartilage and bone matrix
OA
Wound healing
What are the therapeutic uses of Mn as an AO?
Mitochondrial protection from oxidative stress
What are the therapeutic uses of Mn in metabolism?
Blood sugar regulation
Supporting the urea cycle
What can a Mn insufficiency lead to?
Loss of hair colour
Skin rashes
Tendon and bone abnormalities
Who could be at risk of Mn toxicity?
Workers exposed to high Mn dust in air
welders etc
Which nutrients can impair the absorption of Mn?
High intakes of Fe, Ca, Mg
What is the predominant form of Cr?
Trivalent chromium (Cr3+)
What percentage of Cr is absorbed in the intestinal tract?
0.4-2.5%
Food sources of Cr
Broccoli
Barley
Turkey
Black pepper
What is the function of Cr?
Insulin receptor
What is the function of Cr as an insulin receptor?
Component of chromodulin - protein that increases the sensitivity of tyrosine kinase
So when insulin binds to its receptor, its action is enhanced and glucose uptake by the cells is facilitated
Also influences fat and protein metabolism
What are the therapeutic uses of Cr?
Blood sugar regulation DM Insulin resistance Lowering HbA1c Reducing triglycerides
What does Cr deficiency lead to?
Poor blood sugar control
Craving
Fatigue
Anxiety
What can increase Cr excretion?
High carb intake
Vigorous exercise
What can impair the transportation of Cr?
Fe overload (haemochromatosis)
Which detoxification enzymes is Mo a cofactor in?
Sulphite oxidase
Xanthine oxidase
Aldehyde oxidase
Food sources of Mo
Legumes Whole grains Nuts Leafy greens Beef liver Milk
What are the functions of boron?
Mineral metabolism
Bone development
Food sources of boron
Fruit
Veg
Nuts
Legumes
What are the functions of silicon?
Bone mineralisation
Integrity of connective tissue
Food sources of silicon
Whole grains
Root veg
Dried fruit
Bananas
Where can fluoride be mostly found in the body?
Bones
Teeth
What can toxic levels of fluoride harm?
Thyroid gland
Tooth enamel
Which nutrients interact with statins?
Se
Mg
K
How do Mg, Ca and Fe interact with levothyroxine?
Lowers effect of the drug
How does omeprazole interact with Ca, Fe and Zn?
Lowers the amount of them in the body
Which nutrients interact with ACE inhibitors?
Mg
Zn
Fe
Which nutrients interact with anticoagulants?
Se
Zn
Which nutrients interact with antibiotics?
Mg Ca Zn K Fe Mn
Which nutrients interact with diuretics?
Ca
Mg
K
Zn
Which minerals most commonly interact with drugs?
Mg
Ca
Fe
Zn