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.
|
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.
|
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.
|
Chromium is involved in potentiating the action of insulin. Chromium deficiency is relatively rare.
|
The potential role of selenium in cancer prevention has been assessed in humans. One prospective
study of 34,000 men using a nested case-control study design showed that high selenium intakes were
protective against prostate cancer.
|
High intakes of n-6 polyunsaturated fats have been associated with blood lipid profiles
associated with a lower risk of coronary heart disease.
|
Copper is widely distributed in foods with nuts and seeds being major
contributors. Wheat bran cereals and whole grain products are also good sources.
|
The primary role of dietary carbohydrate is the provision of energy to cells, particularly the brain that
requires glucose for its metabolism.
|
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.
|
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.
|
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.
|
The major sources of Riboflavin are milk and milk products and fortified breads and cereals.
|
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.
|
Zinc is widely distributed in foods. Meats, fish and poultry are the major contributors to the diet
but cereals and dairy foods also contribute substantial amounts.
|
Deficiency of Vitamin D results in inadequate mineralisation or demineralisation of the skeleton.
This can lead to rickets in young children, causing bowed legs and knocked knees. In adults, deficiency can lead to
increased bone turnover and osteoporosis.
|
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.
|
Cholesterol comes in 2 main forms: LDL (Low Density Lipoprotein) Cholesterol and HDL (High Density Lipoprotein) Cholesterol. LDL Cholesterol is harmful, and is associated with an increased risk of Coronary Heart Disease(CHD). HDL Cholesterol is beneficial, and reduces the risk of CHD.
|
Vitamin K deficiency causes a bleeding tendency through a lack of activity of the procoagulant
proteins.
|
Folic
acid supplementation in pregnancy can reduce both the occurrence and recurrence of neural tube
defects in the newborn.
|
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.
|
Dietary fibre is the most effective treatment for all forms of constipation due to its influence on faecal
bulk and consistency.
|
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.
|
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.
|
Niacin is involved in energy metabolism,
DNA repair and calcium mobilisation. It functions as part of the intracellular respiration system and with
enzymes involved in oxidation of fuel substrates.
|
Cereal products provide about one-third of the intake of manganese and beverages (tea) and vegetables
are the other major contributors.
|
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.
|
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.
|
In teeth that have erupted, ingestion of fluoride reduces caries due
to reduced acid production by bacteria and increased enamel remineralisation in acidogenic challenge.
|
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.
|
The nine indispensable or essential amino acids, defined as those that the body is unable to synthesise
from simpler molecules, are histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine,
tryptophan and valine.
|
Vitamin B 12 is required for the
synthesis of fatty acids in myelin and, in conjunction with folate, for DNA synthesis.
|
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.
|
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.
|
The best-known role for vitamin
K is the maintenance of normal blood coagulation. The vitamin K-dependent coagulation proteins that are made in the liver have both coagulant and anticoagulant properties.
|
Folate is essential for DNA synthesis. Without folate,
living cells cannot divide. The need for folate is higher when cell turnover is increased, such as in fetal
development. It is also involved in amino acid interconversions.
|
The retinal form of vitamin A is required by the eye to change light to neural signals for vision
|
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.
|
Frank copper deficiency is rare in humans but has been
seen in certain circumstances in infants.
|
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.
|
Dehydration of as little as 2% loss of body weight results in impaired physiological responses and
performance.
|
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.
|
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.
|
The reported health effects of chronic mild dehydration and poor fluid intake include
increased risk of kidney stones, urinary tract cancers, colon
cancer as well as diminished physical
and mental performance.
|
The parent fatty acid of the
n-3 series is alpha-linolenic acid (ALA). ALA primarily functions as a precursor for the synthesis of EPA, which in turn forms DHA (EPA and DHA are Long-Chain n-3 fatty acids)
|
In general, zinc absorption from a diet high in animal protein will be greater than from a diet rich in plant
derived proteins. The requirement for dietary zinc may be as much as 50% greater
for vegetarians, particularly strict vegetarians whose major staples are grains and legumes.
|
Riboflavin and its derivatives are
important for the body's handling of some other nutrients including conversion of vitamin B-6 to its
bioactive form, and conversion of tryptophan to niacin.
|
For infants, breast-feeding is recommended, as the iron in formula is much less bioavailable
(generally only 10-20% as available as that in breast milk)
|
Phosphorus is so widespread in the food supply that
dietary phosphorus deficiency is extremely rare, the exception being long-term, severe food restriction.
|
Clinical deficiency of Vitamin B6 is rare. The symptoms of deficiency include seborrhaeic dermatitis, microcytic anaemia, convulsions, and
depression and confusion
|
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.
|
The major function of Vitamin D in humans is to enhance the ability of the small intestine to absorb calcium from the diet. Vitamin D also plays a role
in enhancing absorption of phosphorus from the diet.
|
Avidin, a
protein found in raw egg white, binds biotin in the gut and prevents its absorption. Although rare, biotin deficiency has been seen in people who consume raw egg white over long
periods.
|
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.
|
Various expert groups have made consensus recommendations for
consumption of ALA and/or the very long chain omega-3s.
The evidence is strongest for reduction of Cardio Vascular Disease risk by EPA and DHA.
|
Choline is widely distributed throughout the food supply. Milk, liver, eggs and peanuts are particularly good sources. Wheat germ and
dried soybeans are good sources of choline for vegetarians.
|
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
|
Selenium functions as an antioxidant and in redox reactions and thyroid metabolism. It is thought to have a role in cellular antioxidant systems.
|
Vitamin C is found in high concentrations in gastric juices where it may prevent the formation of N-nitroso-compounds, which are potential
mutagens.
|
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.
|
Although there is a lack of direct evidence, it is thought that a relationship exists between thiamin
requirement, energy supply and energy expenditure.
|
Water fills the spaces in and between cells and helps
form structures of large molecules such as protein and glycogen. Water is also required for digestion,
absorption, transportation, dissolving nutrients, elimination of waste products and thermoregulation.
|
Calcium is required for the normal development and maintenance of the skeleton as well as for the
proper functioning of neuromuscular and cardiac function.
|
Iron absorption is about 18% from a mixed western diet including animal foods and about 10% from a
plant-based diet; so vegetarians and vegans need higher intakes.
|
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.
|
Unlike most animals, humans and primates lack a key enzyme necessary for the biosynthesis of
vitamin C. We therefore require a dietary source.
|
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.
|
Iron is a component of a number of proteins including haemoglobin. Haemoglobin is important for transport of oxygen to tissues
throughout the body.
|
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.
|
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.
|
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.
|
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.
|
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.
|
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.
|
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
|
Vitamin B 12 can be stored in the liver
for many years.
|
Alcohol intakes
below about 5% of dietary energy are recommended.
|
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.
|
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.
|
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.
|
Zinc is a component of various enzymes that help maintain structural integrity of proteins and
regulate gene expression. The biological function of zinc can
be catalytic, structural or regulatory.
|
With current food supplies
and patterns of eating, it is almost impossible to obtain sufficient vitamin D from the diet alone.
|
If sunlight exposure is adequate, dietary vitamin D can
be considered unnecessary.
|
The amount of protein in the diet is a
factor contributing to the efficiency of zinc absorption as zinc binds to protein.
|
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.
|
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.
|
Fluoride is a normal constituent of the human body, involved in the mineralisation of both teeth and
bones. Because of its role in the prevention of dental caries, fluoride
has been classified as essential to human health.
|
Most of the early signs of deficiency are neurologic or neuromuscular defects that may develop with time into anorexia, nausea, muscular
weakness, lethargy, weight loss, hyper-irritability, hyper-excitability, muscular spasms, tetany and finally
convulsions.
|
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.
|
The major adverse effect of increased sodium chloride intake is elevated blood pressure, a risk factor
for cardiovascular and renal diseases.
|
Thiamin is a water-soluble substance that occurs in free or phosphorylated forms in most plant and
animal tissue.
|
It has been hypothesised that poor
chromium status contributes to the incidence of impaired glucose tolerance and type II diabetes which
has led to interest in a potential role for chromium supplements in type II diabetes.
|
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.
|
Magnesium is required for mitochondria to carry out oxidative phosphorylation. It plays a role in regulating potassium fluxes and in the metabolism of calcium.
|
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
|
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.
|
The main source of vitamin E is fats and oils. It is also found in some vegetables, in the fats of meat,
poultry and fish and, to lesser degrees, in cereals and dairy foods.
|
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%).
|
Phosphate helps to protect blood systemic acid/base balance, acts as a temporary store and transport mechanism for energy and helps in activating
catalytic proteins.
|
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.
|
Vitamin D occurs in two forms. One is produced by the action of sunlight on skin (D 3 or cholecalciferol)
and the other is found in a limited range of foods (D 2 or ergocalciferol).
|
|
