When asked about supplements, health professionals should emphasise the importance of consuming a diet based on healthy eating guidelines. This is a diet rich in starchy, fibrous carbohydrates, including fruit and vegetables,and low in fat, sugar and salt. Dietary supplements do not convert a poor diet into a good one.
Health professionals should be aware of dietary standards and good food sources for nutrients. They should be able to assess an individual’s risk of nutrient deficiency and need for further referral, by asking questions to detect cultural, physical, environmental and social conditions which may predispose to inadequate intakes.
There is a need to be aware of the potential for adverse effects with supplements. Thus, when a client or patient presents with any symptoms, questions should be asked about the use of dietary supplements. Individuals will not always volunteer this information without prompting because they believe that supplements are ‘natural’ and therefore safe. Health professionals should make their clients aware of the existence of badly worded claims and adverts and of the dangers of supplement misuse. Pharmacists have a particular responsibility, simply because they sell these products. When supplying any supplement with perceived health benefits, pharmacists must be careful to avoid giving their professional authority to a product that may lack any health or therapeutic benefit and has risks associated with its use. In accordance with the Code of Ethics of the Royal Pharmaceutical Society of Great Britain, this may involve not stocking or selling the product.
Pharmacists must not give the impression that any dietary supplement is efficacious when there is no evidence for such efficacy. However, providing a product is not harmful for a particular individual, the freedom to use it should be respected. What is important is that consumers are able to make informed and intelligent choices about the products they buy.
Selasa, 22 Februari 2022
Rabu, 22 Februari 2017
Uses of supplements
There are two main approaches to the use of supplements. They can be used to:
• treat or prevent nutritional deficiency; and to
• reduce the risk of non-deficiency disease and promote optimal health.
When vitamins were first discovered during the early years of the 20th century, their only indication was for the prevention and treatment of deficiency disease such as scurvy, beri-beri, pellagra, etc. This led to the development of dietary standards such as RDAs and, more recently, to the Dietary Reference Values (DRVs).
These values were based on amounts of nutrients required to prevent deficiency, and even though subject to various limitations, they are still the best measure of dietary adequacy. After the Second World War, it was thought that nutritional deficiencies had largely disappeared and scientific interest in vitamins and minerals waned. However, with the increase in various chronic diseases such as cardiovascular disease and cancer, vitamins became an area of growing interest again, and itwas suggested that supplements might help to reduce the risk of such disease. At the start of the 21st century, there is growing concern among the public to improve quality of life and supplements are increasingly used to promote so-called optimum health. Despite the idea that nutritional deficiency had disappeared, recent UK national diet and nutrition surveys have shown that there is no room for complacency. Although average dietary intakes may appear adequate, some groups of the surveyed populations are clearly at risk of marginal deficiencies. The National Diet and Nutrition Survey in preschool children4 showed that 8%of the surveyed youngsters aged 11 /2 to 41 /2 were anaemic, a further 12% were mildly iron-deficient and 15% had a poor intake of zinc. Vitamin A deficiency was present in 8%, vitamin B2 deficiency in 23% and vitamin C deficiency in 3%. A similar nutritional survey of older children again showed average nutrient intakes were largely fine, but anaemia was present in 1.5%of boys and 5% of girls, with respective totals of 13% and 27% having low serum ferritin – an indication of iron deficiency. In addition, zinc was found to be low in the diets of 10%of boys and 20% of girls. Also of concern were calcium intakes, which were below the Lower Reference Nutrient Intake (LRNI) in 6%of boys and 12% of girls. For magnesium, the respective figures were 12% and 27% and for vitamin A, 10% and 11%. Furthermore, some of the surveyed youngsters also appeared to have poor status for vitamin B12, vitamin C, vitamin D, folate, riboflavin and thiamine.
The National Diet and Nutrition Survey of people aged 65 years and over6 showed that there were nutritional problems in some individuals. Up to 38%of the survey population was deficient in vitamin D, up to 38% were deficient in vitamin C, up to 18% in folate, up to 15% in vitamin B12 and up to 30% in iron. Of the free-living individuals, 11% of men and 9% of women were anaemic. The most recent National Diet and Nutrition Survey involving British adults aged 19–64 years1 found that mean intakes of all nutrients in men are ≥ 100% of the RNI. For women, mean intakes of iron, magnesium and copper were below the RNI. However, mean intakes fail to show the proportion of people that do not achieve the RNI. For example, for women, mean magnesium intake was 85% of the RNI, but 74% in this survey failed to achieve the RNI.Mean intakes also fail to show that intakes in some age groups are particularly poor. For example, iron intake inwomen overall was 82% of the RNI while in 19–24-year-old women it was 60% of the RNI. Overall, 91% of women failed to achieve the RNI for iron while 41%of women aged 19 to 34 had intakes of iron below the LRNI. For magnesium and copper, intake overall in women is 85% and 86% of the RNI, respectively, but for women aged 19–24 years it was 76% of the RNI for both minerals. Indeed, men and women aged 19–24 had significantly poorer intakes of all vitamins and minerals than those aged 50–64, with mineral and trace element intakes in the women aged 19–24 years a particular cause for concern. Although good diet is the most appropriate route to achieving improved nutrition in these population groups, there is no evidence to suggest that risk of deficiency is a thing of the past.
Various groups of the population could be at risk of nutrient deficiency and could benefit from supplementation. These include:
• People in a particular demographic category, e.g. infants and children, adolescents, women during pregnancy and lactation and throughout the reproductive period, the elderly and ethnic minorities.
• People whose nutritional status may be compromised by lifestyle (enforced or voluntary), e.g. smokers, alcoholics, drug addicts, slimmers, strict vegetarians (i.e. vegans), food faddists, individuals on low incomes and athletes.
• People whose nutritional status may be compromised by surgery and/or disease, e.g. malabsorption syndromes, hepato-biliary disorders, severe burns and wounds and inborn errors of metabolism.
• People whose nutritional status may be compromised by long-term drug administration(e.g. anticonvulsants may increase the requirement for vitamin D).
Increasingly, people are taking supplements for reasons other than prevention of deficiency and at amounts higher than the RDA. Moreover, evidence is increasing that, at least for some nutrients (e.g. folic acid, vitamin D), there may be benefits in achieving higher intakes than the RDA. However, while there is agreement about the beneficial effects of nutrients in the prevention of deficiency disease and the amounts required to achieve such effects, there is controversy about amounts required for reduction in risk of chronic disease and so-called ‘optimum health’. Some would argue that higher amounts are required and that basing requirements for nutrients only on the prevention of deficiency disease is inadequate. But what other end points should be used is open to debate; longevity increased resistance to cancer and coronary heart disease, improved athletic performance etc. Higher levels of intake cannot always easily be obtained from diet alone, and supplementation is required. However, excessive intake of some nutrients can lead to toxicity, and it is with this in mind that several committees worldwide have established safe upper limits for supplement intake.
• treat or prevent nutritional deficiency; and to
• reduce the risk of non-deficiency disease and promote optimal health.
When vitamins were first discovered during the early years of the 20th century, their only indication was for the prevention and treatment of deficiency disease such as scurvy, beri-beri, pellagra, etc. This led to the development of dietary standards such as RDAs and, more recently, to the Dietary Reference Values (DRVs).
These values were based on amounts of nutrients required to prevent deficiency, and even though subject to various limitations, they are still the best measure of dietary adequacy. After the Second World War, it was thought that nutritional deficiencies had largely disappeared and scientific interest in vitamins and minerals waned. However, with the increase in various chronic diseases such as cardiovascular disease and cancer, vitamins became an area of growing interest again, and itwas suggested that supplements might help to reduce the risk of such disease. At the start of the 21st century, there is growing concern among the public to improve quality of life and supplements are increasingly used to promote so-called optimum health. Despite the idea that nutritional deficiency had disappeared, recent UK national diet and nutrition surveys have shown that there is no room for complacency. Although average dietary intakes may appear adequate, some groups of the surveyed populations are clearly at risk of marginal deficiencies. The National Diet and Nutrition Survey in preschool children4 showed that 8%of the surveyed youngsters aged 11 /2 to 41 /2 were anaemic, a further 12% were mildly iron-deficient and 15% had a poor intake of zinc. Vitamin A deficiency was present in 8%, vitamin B2 deficiency in 23% and vitamin C deficiency in 3%. A similar nutritional survey of older children again showed average nutrient intakes were largely fine, but anaemia was present in 1.5%of boys and 5% of girls, with respective totals of 13% and 27% having low serum ferritin – an indication of iron deficiency. In addition, zinc was found to be low in the diets of 10%of boys and 20% of girls. Also of concern were calcium intakes, which were below the Lower Reference Nutrient Intake (LRNI) in 6%of boys and 12% of girls. For magnesium, the respective figures were 12% and 27% and for vitamin A, 10% and 11%. Furthermore, some of the surveyed youngsters also appeared to have poor status for vitamin B12, vitamin C, vitamin D, folate, riboflavin and thiamine.
The National Diet and Nutrition Survey of people aged 65 years and over6 showed that there were nutritional problems in some individuals. Up to 38%of the survey population was deficient in vitamin D, up to 38% were deficient in vitamin C, up to 18% in folate, up to 15% in vitamin B12 and up to 30% in iron. Of the free-living individuals, 11% of men and 9% of women were anaemic. The most recent National Diet and Nutrition Survey involving British adults aged 19–64 years1 found that mean intakes of all nutrients in men are ≥ 100% of the RNI. For women, mean intakes of iron, magnesium and copper were below the RNI. However, mean intakes fail to show the proportion of people that do not achieve the RNI. For example, for women, mean magnesium intake was 85% of the RNI, but 74% in this survey failed to achieve the RNI.Mean intakes also fail to show that intakes in some age groups are particularly poor. For example, iron intake inwomen overall was 82% of the RNI while in 19–24-year-old women it was 60% of the RNI. Overall, 91% of women failed to achieve the RNI for iron while 41%of women aged 19 to 34 had intakes of iron below the LRNI. For magnesium and copper, intake overall in women is 85% and 86% of the RNI, respectively, but for women aged 19–24 years it was 76% of the RNI for both minerals. Indeed, men and women aged 19–24 had significantly poorer intakes of all vitamins and minerals than those aged 50–64, with mineral and trace element intakes in the women aged 19–24 years a particular cause for concern. Although good diet is the most appropriate route to achieving improved nutrition in these population groups, there is no evidence to suggest that risk of deficiency is a thing of the past.
Various groups of the population could be at risk of nutrient deficiency and could benefit from supplementation. These include:
• People in a particular demographic category, e.g. infants and children, adolescents, women during pregnancy and lactation and throughout the reproductive period, the elderly and ethnic minorities.
• People whose nutritional status may be compromised by lifestyle (enforced or voluntary), e.g. smokers, alcoholics, drug addicts, slimmers, strict vegetarians (i.e. vegans), food faddists, individuals on low incomes and athletes.
• People whose nutritional status may be compromised by surgery and/or disease, e.g. malabsorption syndromes, hepato-biliary disorders, severe burns and wounds and inborn errors of metabolism.
• People whose nutritional status may be compromised by long-term drug administration(e.g. anticonvulsants may increase the requirement for vitamin D).
Increasingly, people are taking supplements for reasons other than prevention of deficiency and at amounts higher than the RDA. Moreover, evidence is increasing that, at least for some nutrients (e.g. folic acid, vitamin D), there may be benefits in achieving higher intakes than the RDA. However, while there is agreement about the beneficial effects of nutrients in the prevention of deficiency disease and the amounts required to achieve such effects, there is controversy about amounts required for reduction in risk of chronic disease and so-called ‘optimum health’. Some would argue that higher amounts are required and that basing requirements for nutrients only on the prevention of deficiency disease is inadequate. But what other end points should be used is open to debate; longevity increased resistance to cancer and coronary heart disease, improved athletic performance etc. Higher levels of intake cannot always easily be obtained from diet alone, and supplementation is required. However, excessive intake of some nutrients can lead to toxicity, and it is with this in mind that several committees worldwide have established safe upper limits for supplement intake.
Minggu, 22 Februari 2009
Role of the Health professional
When asked about supplements, health professionals should emphasise the importance of consuming a diet based on healthy eating guidelines. This is a diet rich in starchy, fibrous carbohydrates, including fruit and vegetables,and low in fat, sugar and salt. Dietary supplements do not convert a poor diet into a good one.
Health professionals should be aware of dietary standards and good food sources for nutrients. They should be able to assess an individual’s risk of nutrient deficiency and need for further referral, by asking questions to detect cultural, physical, environmental and social conditions which may predispose to inadequate intakes.
There is a need to be aware of the potential for adverse effects with supplements. Thus, when a client or patient presents with any symptoms, questions should be asked about the use of dietary supplements. Individuals will not always volunteer this information without prompting because they believe that supplements are ‘natural’ and therefore safe. Health professionals should make their clients aware of the existence of badly worded claims and adverts and of the dangers of supplement misuse. Pharmacists have a particular responsibility, simply because they sell these products. When supplying any supplement with perceived health benefits, pharmacists must be careful to avoid giving their professional authority to a product that may lack any health or therapeutic benefit and has risks associated with its use. In accordance with the Code of Ethics of the Royal Pharmaceutical Society of Great Britain, this may involve not stocking or selling the product.
Pharmacists must not give the impression that any dietary supplement is efficacious when there is no evidence for such efficacy. However, providing a product is not harmful for a particular individual, the freedom to use it should be respected. What is important is that consumers are able to make informed and intelligent choices about the products they buy.
Health professionals should be aware of dietary standards and good food sources for nutrients. They should be able to assess an individual’s risk of nutrient deficiency and need for further referral, by asking questions to detect cultural, physical, environmental and social conditions which may predispose to inadequate intakes.
There is a need to be aware of the potential for adverse effects with supplements. Thus, when a client or patient presents with any symptoms, questions should be asked about the use of dietary supplements. Individuals will not always volunteer this information without prompting because they believe that supplements are ‘natural’ and therefore safe. Health professionals should make their clients aware of the existence of badly worded claims and adverts and of the dangers of supplement misuse. Pharmacists have a particular responsibility, simply because they sell these products. When supplying any supplement with perceived health benefits, pharmacists must be careful to avoid giving their professional authority to a product that may lack any health or therapeutic benefit and has risks associated with its use. In accordance with the Code of Ethics of the Royal Pharmaceutical Society of Great Britain, this may involve not stocking or selling the product.
Pharmacists must not give the impression that any dietary supplement is efficacious when there is no evidence for such efficacy. However, providing a product is not harmful for a particular individual, the freedom to use it should be respected. What is important is that consumers are able to make informed and intelligent choices about the products they buy.
Dietary Supplement Classification
Dietary supplements fall into several categories in relation to ingredients. These are:
1 Vitamins and minerals
· Multivitamins and minerals. These normally contain around 100% of the Recommended Daily Allowance (RDA) for vitamins, with varying amounts of minerals and trace elements.
· Single vitamins and minerals. These may contain very large amounts, and when levels exceed ten times the RDA, they are often termed ‘megadoses’.
· Combinations of vitamins and minerals. These may be marketed for specific population groups, e.g. athletes, children, pregnant women, slimmers, teenagers, vegetarians, etc.
· Combinations of vitamins and minerals with other substances, such as evening primrose oil and ginseng.
2 ‘Unofficial’ vitamins and minerals, for which a requirement and a deficiency disorder in humans has not, so far, been recognised, e.g. boron, choline, inositol, silicon.
3 Natural oils containing fatty acids for which there is some evidence of beneficial effects, e.g. evening primrose oil and fish oils.
4 Natural substances containing ‘herbal’ ingredients with recognised pharmacological actions but whose composition and effects have not been fully defined, e.g. echinacea, garlic, ginkgo biloba and ginseng.
5 Natural substances whose composition and effects are not well defined but which are marketed for their ‘health giving properties’, e.g. chlorella, royal jelly and spirulina.
6 Enzymes with known physiological effects, but of doubtful efficacy when taken by mouth, e.g. superoxide dismutase.
7 Amino acids or amino acid derivatives, e.g. N-acetyl cysteine, S-adenosyl methionine.
1 Vitamins and minerals
· Multivitamins and minerals. These normally contain around 100% of the Recommended Daily Allowance (RDA) for vitamins, with varying amounts of minerals and trace elements.
· Single vitamins and minerals. These may contain very large amounts, and when levels exceed ten times the RDA, they are often termed ‘megadoses’.
· Combinations of vitamins and minerals. These may be marketed for specific population groups, e.g. athletes, children, pregnant women, slimmers, teenagers, vegetarians, etc.
· Combinations of vitamins and minerals with other substances, such as evening primrose oil and ginseng.
2 ‘Unofficial’ vitamins and minerals, for which a requirement and a deficiency disorder in humans has not, so far, been recognised, e.g. boron, choline, inositol, silicon.
3 Natural oils containing fatty acids for which there is some evidence of beneficial effects, e.g. evening primrose oil and fish oils.
4 Natural substances containing ‘herbal’ ingredients with recognised pharmacological actions but whose composition and effects have not been fully defined, e.g. echinacea, garlic, ginkgo biloba and ginseng.
5 Natural substances whose composition and effects are not well defined but which are marketed for their ‘health giving properties’, e.g. chlorella, royal jelly and spirulina.
6 Enzymes with known physiological effects, but of doubtful efficacy when taken by mouth, e.g. superoxide dismutase.
7 Amino acids or amino acid derivatives, e.g. N-acetyl cysteine, S-adenosyl methionine.
What are dietary supplements?
Various definitions for dietary supplements exist worldwide. In the UK, the definition developed by the Proprietary Association of Great Britain (PAGB), British Herbal Manufacturers’ Association (BHMA) and the Health Food Manufacturers’ Association (HFMA) is that they are:
Foods in unit dosage form, e.g. tablets, capsules and elixirs, taken to supplement the diet. Most are products containing nutrients normally present in foods which are used by the body to develop cells,bone, muscle etc, to replace co-enzymes depleted by infection and illness, and generally to maintain good health.
In addition to vitamins and minerals, this definition also covers ingredients such as garlic, fish oils,evening primrose oil and ginseng, which can be taken to supplement dietary intake or for their suggested health benefits. For the purposes of the European Union (EU) Directive on food supplements the term ‘food supplements’ means:
Foodstuffs the purpose of which is to supplement the normal diet and which are concentrated sources of nutrients or other substances with a nutritional or physiological effect, alone or in combination, marketed in dose form, namely forms such as capsules, pastilles, tablets, pills and other similar forms, sachets of powder, ampoules of liquids, drop dispensing bottles, and other similar forms of liquids and powders designed to be taken in measured small unit quantities.
In the USA, the Dietary Supplement Health Education Act (DSHEA) 1994 defines a dietary supplement as:
A product (other than tobacco) that is intended to supplement the diet which bears or contains one or more of the following dietary ingredients: a vitamin, a mineral, a herb or other botanical, an amino acid, a dietary substance for use by man to supplement the diet by increasing the total daily intake, or a concentrate, metabolite, constituent, extract or combinations of these ingredients. It is intended for ingestion in pill, capsule, tablet or liquid form, is not represented for use as a conventional food or as the sole item of a meal or diet and is labelled as a dietary supplement.
This definition, like that in the UK, also expands the meaning of dietary supplements beyond essential nutrients, to include such substances as ginseng, garlic, psyllium, other plant ingredients, enzymes, fish oils and mixtures of these. The EU definition does not currently include substances apart from vitamins and minerals,but other substances may be included in the future.
One of the key points in these definitions is that dietary supplements are products consumed in unit quantities in addition to normal food intake. This differentiates supplements from other foods, such as fortified foods and functional foods, to which nutrients are added. However, a major difference in the US definition is the explicit inclusion of ‘herbs or other botanicals’ in the list of dietary ingredients. In the UK, herbal products are currently marketed under a variety of arrangements – either as fully licensed medicines, under the Traditional Herbal Medicines Product (THMP)
Directive, ‘medicines exempt from licensing’ under section 12 of the 1968 Medicines Act, or as cosmetics or foods, so they do not fall entirely in the food supplements category. Enteral feeds (e.g. Complan and Ensure) and slimming aids are also classified as dietary supplements by nutritionists and dieticians, but for the purposes of this book, these products will be ignored.
Foods in unit dosage form, e.g. tablets, capsules and elixirs, taken to supplement the diet. Most are products containing nutrients normally present in foods which are used by the body to develop cells,bone, muscle etc, to replace co-enzymes depleted by infection and illness, and generally to maintain good health.
In addition to vitamins and minerals, this definition also covers ingredients such as garlic, fish oils,evening primrose oil and ginseng, which can be taken to supplement dietary intake or for their suggested health benefits. For the purposes of the European Union (EU) Directive on food supplements the term ‘food supplements’ means:
Foodstuffs the purpose of which is to supplement the normal diet and which are concentrated sources of nutrients or other substances with a nutritional or physiological effect, alone or in combination, marketed in dose form, namely forms such as capsules, pastilles, tablets, pills and other similar forms, sachets of powder, ampoules of liquids, drop dispensing bottles, and other similar forms of liquids and powders designed to be taken in measured small unit quantities.
In the USA, the Dietary Supplement Health Education Act (DSHEA) 1994 defines a dietary supplement as:
A product (other than tobacco) that is intended to supplement the diet which bears or contains one or more of the following dietary ingredients: a vitamin, a mineral, a herb or other botanical, an amino acid, a dietary substance for use by man to supplement the diet by increasing the total daily intake, or a concentrate, metabolite, constituent, extract or combinations of these ingredients. It is intended for ingestion in pill, capsule, tablet or liquid form, is not represented for use as a conventional food or as the sole item of a meal or diet and is labelled as a dietary supplement.
This definition, like that in the UK, also expands the meaning of dietary supplements beyond essential nutrients, to include such substances as ginseng, garlic, psyllium, other plant ingredients, enzymes, fish oils and mixtures of these. The EU definition does not currently include substances apart from vitamins and minerals,but other substances may be included in the future.
One of the key points in these definitions is that dietary supplements are products consumed in unit quantities in addition to normal food intake. This differentiates supplements from other foods, such as fortified foods and functional foods, to which nutrients are added. However, a major difference in the US definition is the explicit inclusion of ‘herbs or other botanicals’ in the list of dietary ingredients. In the UK, herbal products are currently marketed under a variety of arrangements – either as fully licensed medicines, under the Traditional Herbal Medicines Product (THMP)
Directive, ‘medicines exempt from licensing’ under section 12 of the 1968 Medicines Act, or as cosmetics or foods, so they do not fall entirely in the food supplements category. Enteral feeds (e.g. Complan and Ensure) and slimming aids are also classified as dietary supplements by nutritionists and dieticians, but for the purposes of this book, these products will be ignored.
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