Vitamin E deficiency symptoms have never been described. Deficiency occurs only as a result of genetic abnormalities, fat malabsorption syndrome, or protein-energy malnutrition.
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Polyunsaturated fatty acids contain two or more double bonds. The most common is Linoleic Acid. It is described as 'omega-6' due to the position of the double bonds and occurs in seed oils,
eg sunflower, safflower and corn.
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Functional indicators of iron deficiency may include reduced physical work capacity, delayed
psychomotor development in infants, impaired cognitive function, impaired immunity and adverse
pregnancy outcomes.
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Energy is released from food
components by oxidation. The main sources of energy are carbohydrates, proteins, fats and, to a lesser
degree, alcohol.
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Dehydration of as little as 2% loss of body weight results in impaired physiological responses and
performance.
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Pantothenic acid deficiency is very rare. Symptoms of a deficiency of Pantothenic acid include irritability, restlessness, fatigue, apathy, malaise, sleep disturbance, nausea,
vomiting and cramping, numbness and staggering gait, as well as hypoglycaemia and increased insulin
sensitivity.
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Molybdenum is involved in catabolism of sulphur amino acids and heterocyclic compounds
including purines and pyridines.
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Iodine was one of the first trace elements to be identified as essential. In the 1920s it was shown
to be an integral component for normal growth and metabolism. Soon after, it was recognised as a key regulator of important cell processes.
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The main monounsaturated fatty acid is oleic acid with one double bond. Olive, canola and peanut oils
are rich in oleic acid. The monounsaturates are synthesised by the body and are thus not required
in the diet.
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Vitamin K deficiency causes a bleeding tendency through a lack of activity of the procoagulant
proteins.
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Phosphorus is widely distributed in natural foods and also found in food additives as phosphate salts,
used in processing for retaining moisture, smoothness and binding.
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The environment within the gastrointestinal
tract, which can be affected by other dietary constituents, markedly influences the solubility and
absorptive efficiency of zinc.
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Pantothenic acid is
involved in fatty acid metabolism. It is essential to almost all forms of life
and is widely distributed in foods. Chicken, beef, potatoes, oat-based cereals, tomato products, liver,
kidney, egg yolks and whole grains are major sources in western diets.
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Deficiency of niacin causes the disease pellagra which is associated with inflammation of the skin on
exposure to sunlight, resembling severe sunburn except that the affected skin is sharply demarcated. Pellagra is the disease of 'three Ds', namely dermatitis, diarrhoea and (in
severe cases) delirium or dementia.
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A 10-year study of skin cancer in the US initially found no effect of supplemental selenium at 200 μg/
day on basal cell or squamous cell skin cancer, but significant reduction in total cancer and cancers of
the prostate, lung and colorectum.
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Frank copper deficiency is rare in humans but has been
seen in certain circumstances in infants.
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Phosphorus is the second most abundant inorganic element in the body and is a part of many important
compounds. Phosphorus as phosphate is a major buffer of acid in urine by
virtue of its monovalent, divalent and trivalent forms.
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With current food supplies
and patterns of eating, it is almost impossible to obtain sufficient vitamin D from the diet alone.
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High intakes of n-6 polyunsaturated fats have been associated with blood lipid profiles
associated with a lower risk of coronary heart disease.
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Iodine is an integral component of a key thyroid hormone. The thyroid hormones are required for normal growth and development of tissues such as the central nervous system and have a broader role in maturation of the
body as a whole. They are important for energy production and oxygen consumption in cells thereby helping to maintain the body's metabolic rate.
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Protein occurs in all living cells and has both functional and structural properties. Amino acids,
assembled in long chains, are the building blocks of protein.
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Magnesium is widely distributed in the food supply in both plant and animal foods. Most green
vegetables, legumes, peas, beans and nuts are rich in magnesium, as are some shellfish and spices.
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The retinal form of vitamin A is required by the eye to change light to neural signals for vision
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It has been postulated that diets high in fibre have a lower energy density and may therefore help in moderating obesity.
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Molybdenum is absorbed very efficiently over a wide range of
intakes. No clear deficiency syndrome has been seen in animals even with
major reductions in molybdoenzymes.
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Dietary intake of iron at levels found in some supplements can decrease zinc absorption, which is
of particular concern in the management of pregnancy and lactation.
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Sodium is found in most foods as sodium chloride, generally known as 'salt'. Sodium is a cation needed to maintain extracellular volume and serum osmolality.
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Choline is a precursor for a number of compounds including the neurotransmitter acetylcholine. It is also important for lipid and cholesterol transport and metabolism if methyl groups.
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Folic
acid supplementation in pregnancy can reduce both the occurrence and recurrence of neural tube
defects in the newborn.
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Thiamin is a water-soluble substance that occurs in free or phosphorylated forms in most plant and
animal tissue.
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Vitamin C deficiency causes scurvy, symptoms of which include skeletal and vascular lesions with
gingival changes, pain in the extremities, haemorrhage, oedema, ulcerations and death.
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Vitamin C is found in high concentrations in gastric juices where it may prevent the formation of N-nitroso-compounds, which are potential
mutagens.
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Adequate intake of
vitamin B 12 is essential for normal blood function and neurological function.
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Beri beri is one of two distinct major diseases from deficiency of thiamin. In acute
beri beri there is a high output cardiac failure, warm extremities, bounding pulse, oedema and cardiac
enlargement.
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Calcium balance deteriorates at menopause. In post menopausal women, there is evidence that a high
calcium intake will slow the rate of bone loss and may reduce the risk of fracture.
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Calcium is required for the normal development and maintenance of the skeleton as well as for the
proper functioning of neuromuscular and cardiac function.
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In Australia, the National Nutrition Survey of 1995 indicated that 45% of dietary fibre comes from breads
and other cereal foods, 10% from fruit and 30% from vegetables.
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Chronically high levels of alcohol ingestion can negatively affect vitamin A status through an effect on
the liver.
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Vitamin C is found widely in fruits and vegetables. Fruits such as blackcurrants, guava, citrus, and
kiwi fruit and vegetables such as broccoli and sprouts are good sources.
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In excess, Manganese can interfere with iron absorption.
Manganese is excreted rapidly into the gut through bile and lost primarily in faeces. Low bile excretion can therefore increase the potential for manganese toxicity
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The amount of energy needed for the internal bodily functions necessary for life (eg cell metabolism, synthesis and metabolism of enzymes and hormones) is called the basal metabolic rate (BMR). BMR represents about 45-70% of daily energy expenditure.
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Chromium is involved in potentiating the action of insulin. Chromium deficiency is relatively rare.
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A seasonal variation in vitamin D levels occurs in Australia. In the
Geelong Osteoporosis Study, the mean vitamin D levels for winter were 58 nmol/L compared with
70 nmol/L in summer
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Cereal products provide about one-third of the intake of manganese and beverages (tea) and vegetables
are the other major contributors.
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The major adverse effect of increased sodium chloride intake is elevated blood pressure, a risk factor
for cardiovascular and renal diseases.
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Phosphorus is so widespread in the food supply that
dietary phosphorus deficiency is extremely rare, the exception being long-term, severe food restriction.
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Amino acids are used for the
synthesis of body proteins and other metabolites, and can also be used as a source of dietary energy.
The proteins of the body are continually being broken down and resynthesised in a process called
protein turnover.
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Vitamin C, in addition to providing its own benefits, interacts with other nutrients. It aids in the absorption of iron and copper, the maintenance of glutathione in the reduced form, the regeneration, or sparing, of alpha-tocopherol and the
stabilisation of folate.
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Potassium blunts the effect of sodium chloride on blood pressure, mitigating salt sensitivity and lowering urinary calcium excretion.It has been hypothesised that high protein-low potassium diets could induce a low-grade metabolic acidosis that could induce demineralisation of bone, osteoporosis and kidney stones.
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Dental caries is often identified
as the limiting factor in terms of an upper intake of cariogenic sweeteners, even in an era of fluoride
exposure.
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Low intakes of calcium have been associated with a condition of low
bone density called osteoporosis which is quite common in western cultures and which often results in
bone fracture.
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Iron in foods can come in two general forms - as
haem or non-haem iron. Iron from animal food sources such as meat, fish and poultry may be either
haem or non-haem whereas the iron in plant sources such grains and vegetables is non-haem.
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Selenium functions as an antioxidant and in redox reactions and thyroid metabolism. It is thought to have a role in cellular antioxidant systems.
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There is some evidence that choline may improve cognitive function and memory at all ages and,
by extension, choline deficiency has been implicated in poor performance for groups such as the
institutionalised elderly.
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Vitamin A is a fat-soluble vitamin which helps maintain normal reproduction, vision and immune
function. Vitamin A intakes or requirements are generally expressed in terms of retinol equivalents (RE). Retinol is required for the integrity of epithelial cells throughout the body.
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Because of its role in energy metabolism, niacin
requirements are, to some extent, related to energy requirements.
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The dietary essentiality of choline was demonstrated in a study of healthy men with
normal folate and vitamin B 12 status who developed liver damage with lower plasma choline and
phosphatidylcholine concentrations when fed a choline-deficient diet.
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Selenium is found in a range of foods, the content of which varies with geographic sources of the
food. Soil concentrations can range from <0.01 μg/g to >1,000 μg/g with plant food content reflecting
this range.
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Vitamin B6 is found in a wide range of foods including organ meats, muscle meats, breakfast cereals,
vegetables and fruits.
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The primary role of dietary carbohydrate is the provision of energy to cells, particularly the brain that
requires glucose for its metabolism.
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Molybdenum is found in plant foods and reflects the soil content in which they grow. Legumes are
major contributors of molybdenum in the western diet, as are grain products and nuts.
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Magnesium is a cofactor for more than 300 enzyme systems and is involved in
both aerobic and anaerobic energy generation and in glycolysis.
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Magnesium is required for mitochondria to carry out oxidative phosphorylation. It plays a role in regulating potassium fluxes and in the metabolism of calcium.
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Wernicke's encephalopathy is one of two distinct major diseases from deficiency of thiamin. It is usually seen in people who have been drinking alcohol heavily and eating very little. (Alcohol requires thiamin for its metabolism). The characteristic feature is paralysis of one or more of the external
movements of the eyes.
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The major role of vitamin E is to protect polyunsaturated fatty acids from oxidation. It acts as
an anti-oxidant in the lipid phase of cell membranes.
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Osteoporosis is one of the major causes of morbidity amongst older Australians and New Zealanders,
particularly postmenopausal women.
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Calcium intake throughout life is a major factor affecting the
incidence of osteoporosis, however other factors, notably adequate vitamin D status and exercise, also
play a role.
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Copper is widely distributed in foods with nuts and seeds being major
contributors. Wheat bran cereals and whole grain products are also good sources.
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Processing of food (cutting up,
cooking etc) greatly improves availability and thus absorption of carotenoids from foods.
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To achieve iron balance, adult
men need to absorb about 1 mg/day and adult menstruating women about 1.5 mg/day, although
this is highly variable. Towards the end of pregnancy, the absorption of 4-5 mg/day of iron is necessary.
Requirements are higher during periods of rapid growth in early childhood and adolescence
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If sunlight exposure is adequate, dietary vitamin D can
be considered unnecessary.
|
Vitamin B 12 deficiency can produce haematological, neurological or gut symptoms. The underlying problem is interference with DNA synthesis leading to production of
abnormally large erythrocytes.
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Adequate dietary fibre is essential for proper functioning of the gut and has also been related to risk
reduction for a number of chronic diseases including heart disease, certain cancers and diabetes.
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Linoleic Acid, the most common Polyunsaturated fatty acid, is involved in the regulation of gene expression. Linoleic Acid is also found as a structural component of cell membranes and is important in
cell signalling.
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The major sources of Riboflavin are milk and milk products and fortified breads and cereals.
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Long Chain (LC) n-3 fatty acids (EPA, DHA, and DPA) are found predominantly in oily fish such as mackerel,
herrings, sardines, salmon and tuna and other seafood.
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Energy is not a nutrient but is required in the body for metabolic processes, physiological functions,
muscular activity, heat production, growth and synthesis of new tissues.
|
All of the necessary amino acids can be provided in the amounts needed from plant
sources.
|
Alcohol intakes
below about 5% of dietary energy are recommended.
|
People with hypertension, diabetes and chronic kidney disease and greater age tend to be more
sensitive to the blood pressure raising effects of sodium chloride intake. Being overweight also appears to
increase susceptibility.
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An increase in saturated fat intake leads to an increase in harmful LDL (Low Density Lipoprotein) cholesterol, which leads to a greater risk of Coronary Heart Disease.
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In the last decade, there has been
an exponential rise in publications on health benefits of omega-3 polyunsaturated fatty acids, particularly the longer chain
omega-3s, EPA, DPA and DHA.
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Potassium is the major cation of intracellular fluid and an almost constant component of lean body
tissues. Potassium requirements can be affected by climate and physical activity, the use of diuretics, and the
intake of other electrolytes, notably sodium.
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Vitamin B 12 can be stored in the liver
for many years.
|
Symptoms of biotin deficiency include dermatitis, conjunctivitis,
alopecia and Central Nervous System (CNS) abnormalities, including developmental delay in infants. People with
genetic biotinidase deficiency will have increased requirements.
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The major dietary sources
of vitamin K are green leafy vegetables such as kale, spinach, salad greens, cabbage, broccoli and
brussel sprouts and certain plant oils such as soybean and canola oils.
|
Dietary fibre intakes have been linked to reduced risk of CHD, mainly through an effect on
plasma cholesterol. Complete vegetarians typically have higher ratios of high density lipoprotein (HDL) "Good" cholesterol to total cholesterol than either lacto-ovo-vegetarians or nonvegetarians.
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Calcium is stored in the teeth and bones, where it
provides structure and strength.
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The main sources of folate in Australia and New Zealand are cereals, cereal
products and dishes based on cereals (about 27%) and vegetables and legumes (about 29%). Fruit
provides about 8-10%. Orange juice is contributing a greater amount than in the past due to the recent
introduction of fortification with folate.
|
The parent n-3 fatty acid, ALA, aids in the formation of EPA and DHA, but the conversion of ALA to EPA and DHA is limited, creating the need for a dietary source
|
Fluoride has a unique ability to stimulate new
bone formation and as such has been used as an experimental drug for the treatment of osteoporosis
|
Riboflavin deficiency can
result in raised plasma levels of homocysteine that are associated with increased cardiovascular risk. The classic disease of riboflavin deficiency is ariboflavinosis, which manifests in growth disturbances, seborrhaeic dermatitis, inflammation of the oral mucosa and tongue, cracks at the corner of the mouth
and normocytic anaemia.
|
Ingestion of fluoride in the pre-eruptive development of teeth has the effect of reducing caries due to
uptake of fluoride by enamel crystallites and formation of fluorohydroxyapatite.
|
Omega-3 fatty acids are so named due to a double chemical bond at the n-3 position in the molecule. Humans are unable to insert a double
bond at the n-3 position of a fatty acid and thus require a dietary source.
|
Saturated fatty
acids have both physiological and structural functions. They can be synthesised by the body so are not
required in the diet.
|
Recommended carbohydrate intake in adults and children is 45-65% of
dietary energy intake. There is believed to be an increased risk for Coronary Heart Disease at high carbohydrate intakes (>65%) and increased risk of obesity with low carbohydrate, high fat intakes (<45%).
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Haem iron is more bioavailable to humans than the non-haem. The presence of other nutrients such as vitamin C and organic acids such as citric, lactic or malic acid
can increase the absorption of non-haem iron.
|
Retinoic acid plays an important role in
embryonic development, particularly in the development of the spinal cord and vertebrae, limbs, heart,
eye and ears
|
Leafy green vegetables, vine fruit such as tomatoes, cucumbers, zucchini, eggplant and pumpkin,
and root vegetables are particularly good sources of Potassium. It is also moderately abundant in
beans peas, tree fruits, milks, yoghurts and meats.
|
Copper deficiency results in defects in connective tissue that lead to vascular and skeletal problems, and
anaemia related to defective iron metabolism. It can also affect the central nervous system and the immune and cardiovascular systems, notably in infants.
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