Examining the effectiveness of Health Supplements
1.1 Background and problem statement
The prevalence used of health supplements especially multivitamins and minerals in many developed counteries are widened eventhough their effectiveness is unclearly determined (Rock , 2007). Based on the data collected by National Health and Nutrition Examination Survey (NHANES) 1999-2000, 52 percent of US adults reported taking a dietary supplement in the past month and 35 percent is reported on regular use of a multivitamin-multimineral product. Marketing data from Nutrition Business Journal of year 1997 till 2001 show a dramatic increase in supplement sales and estimated total approximately $ 18.8 billion in 2003. In Malaysia, according to the data published by Icon Health Publication from R & D Committee at INSTEAD, the latent demand for vitamin and dietary supplement has growing increasing from year to year.
Since the use of health supplements continues to expand in future, thus investigating of preliminary reason behind this trend is important. Supplement consumption usually occurs in the context of achieving or maintaining a healthy lifestyle. Several studies
have been suggested that individuals might tend to use health supplements in order to compensate for unhealthy behaviours (Hilliam, 1996; Kirk et al., 1999; Radimer et al., 2000). One of the important reason that contribute to the increased use of health supplement is widely availability of these agents, in part because of the minimal regulatory requirements for safety and efficacy compared with regulatory requirements for drugs. Despite the fact that health supplements are not classified as drugs by the US Food and Drug Administration (FDA), the 1994 Dietary Supplement Health and Education Act allows manufacturers to make claims intended to attract public opinion regarding the benefits on the use of these supplement products. Under DSHEA, product labels cannot claim to diagnose, treat, cure or prevent any disease but it only claims to support the structure and function of the body.  Basically, consumption of health supplements can also be categorized as one of the type of complementary or alternative medicine (CAM).
1.2 Significance of the study
Anecdotally, there is an increasing use of health supplements among Malaysian. However, relatively little is known about the patterns of use of health supplements among them. Therefore, there is a need for continued research in order to provide more knowledge related to the benefit of supplement use. To our knowledge, only one study conducted by International Medical University, has focused specifically on the usage and opinion among health sciences students on the dietary supplements. Eventhough usage of health supplement is prevalent but there are only a few published reports (Mazlan, 1990; Safiah, 2002). In parallel with the implementation of National Plan of Action for Nutrition II of Malaysia (NPANM), there is a need for continued research in order to investigate the use, attitudes and knowledge of health supplements among urban adults in Klang Valley which still represents the area with the highest prevalence of health supplement’s user in Malaysia.
The purpose of this study was to assess the use of health supplements among Malaysian’s urban adults . This study not only focused on herbal supplements but it also include functional foods, nutrient and botanical products available in the market. Besides, we like to determine whether attitudes are better predictor of adult’s intentions to use health supplements than are subjective norms. Last but not least is to assess knowledge concerning the safety of health supplements among urban adults.
2.1 Health supplement
2.1.1 Definition of health supplement
Health supplement is a term that also commonly known as dietary supplement, nutraceutical supplement or nutritional supplement. Eventhough this term has been used interchangeably, but the meaning of them is still same. In early 1990s, a nutraceutical term was coined by Dr. Stephen DeFelice and it was defined concisely as any substance either food or a part of food. It has a wider range from specific diet, isolated nutrients, processed foods, dietary supplements to genetically modified foods and also include herbal products. It was intended to be use to provides health benefits to the end user (Barnett et al., 1996). Before year 1994, the health supplement was subjected to the same regulatory requirement as other food. However, in October 1994, the President Clinton was assigned a new act under FDA regulations that known as Dietary Supplement Health and Education Act. According to the DSHEA, dietary supplement is defined as a product that intended to be taken orally in order to supplement the diet in which it contains a dietary ingredient. The dietary ingredients in these products may include vitamins, minerals, herbs or other botanicals, amino acids, and substances such as enzymes, organ tissues, glandulars and metabolites. It can also be extracts or concentrates, and may be found in many forms such as tablets, capsules, softgels, gelcaps, liquids or powders (U.S Food and Drug Administration, 1995).
Whatever dosage form it is, this dietary ingredient is not considered as a drug. In case of a drug, it was subjected to undergo some procedures in order to be clinically proven safe to be used. However, dietary supplement was treated reverse to this way since that it was considered safe until proven unsafe. In addition, dietary ingredient could be used in dietary supplement without a need to get approval from FDA as food additive and generally recognised as safe (GRAS) ingredients (Susan Onel, 2005). Due to the minimal regulatory requirements of safety and its efficacy, therefore the health supplement become more widely available and this contributed to increase of its used (Bardia et al., 2007). However, in case of a new dietary ingredient present in the product then the manufacturers of dietary supplement must have to provide FDA with evidence by submission of the product’s safety data of at least 75 days prior to its release to the public. This dietary ingredient was considered as a new ones if it was not marketed in U.S before October 15, 1994 (Cohen, 2000).
2.1.2 Definition of health supplement user
Generally, health supplement users are those healthy people who are seeking for supplements as a one of several alternatives for improving health (Sheldon & Pelletier, 2003). In U.S, it has been estimated that approximately half of their adult population considered as users of health supplements (Robson et al., 2008 ; Radimer et al., 2004). A study done by Knudsen et al. in year 1997 to 1998 at two Danish cities was defined a health supplement user as a person who consumed at least one type of supplements within a period of time of the survey. Basically, Knudsen and his colleagues determined those supplement users based on their frequency intake. Result indicated that from 2758 of supplement users about 27 percent of them took more than one health supplement per day and twelve percent took three or more per day (Knudsen et al., 2002).
In the present study persons who consumed any health supplement at least once in a year has been considered as dietary or health supplement users. In this study, they defined health supplement users into three groups which are daily user, weekly user and seldom user. The daily users are those who reported use of any health supplement once a day or more for the past 12 months whereas weekly users are those who reported use once a week or more but must be less than once a day for the past 12 months and seldom users are those people who reported use once a year or more but less than once a week for the past 12 months (Imai et al., 2006).
2.1.3 Types of health supplements
With the increased in health awareness regarding the use of health supplements, the public is flooded by numerous health supplement products which are frequently advertised through the various media. Thus, there are many types of health supplements that have been practically used by the supplement user.
Vitamin is a group of complex organic compounds that present in small amounts in natural foodstuffs which are play an essential role for the body to regulate normal metabolism and lack of which in the diet causes deficiency diseases (McDowell, 2000). Since vitamin can be found in daily food consumption thus for a normal healthy people intake of vitamin supplement is unnecessary. This is because overconsumption of certain vitamin such as vitamin A may lead to reversible Acute hypervitaminosis that occur after ingestion of more than or equal to 500,000 IU (over 100 times the RDA) by adults (Bendich & Langseth, 1989). According to the survey done among 129 doctors working at hospitals in Kota Bharu, the results showed that the health supplements commonly used were multivitamins and minerals (92.3 percent) whereas prevalence used of vitamin C is 26.9 percent (Rohana & Zulkifli, 2007). The types and usage patterns of health supplements used as shown in Table 2.1
Table 2.1 : Types and used patterns of health supplements among doctors
Rank Supplement/s Regular users Sporadic users Total (%)
1 MVT plus minerals 14 1 15 (17.9)
2 Vitamin Bco 12 3 15 (17.9)
3 Vitamin C 10 1 11 (13.1)
4 Garlic 7 0 7 (8.3)
5 MVT only 5 1 6 (7.1)
6 Traditional 4 1 5 (6.0)
7 Lecithin 4 0 4 (4.8)
8 Prenatal vitamins 3 0 3 (3.6)
9 Vitamin E 3 0 3 (3.6)
10 Fish oil 2 1 3 (3.6)
11 Ginseng 2 1 3 (3.6)
12 Iron/Folic acid 2 0 2 (2.4)
13 Bee Pollen 1 1 2 (2.4)
14 Others 5 0 5 (6.0)
TOTAL 74 10 84 (100.0)
Source : Malaysian Journal of Public Health Medicine 2007, Vol. 7(1):60-63
Minerals are nonorganic substances found in all body tissues and fluids such as bones, teeth, brain, liver, muscle, blood and nerve cells. They are required in modest amounts for the maintenance of structural integrity of essential molecules and development of optimal physiological function (Lukaski, 1995). Since minerals cannot be synthesized by the body therefore they must be consumed through a healthy diet. Based on the data from the NILS-LSA done in Japan, about 55 percent of males and 61 percent of females were consumed some type of health supplements and revealed that calcium was the most popular mineral consumed by both sexes ( Imai et al., 2006). In addition the study done by Chandra and his colleagues were investigated the respondents regarding to their reasons for consuming mineral supplements and their knowledge on mineral supplements. Thus, the finding of this study revealed that the most prevelent reason for consuming mineral supplements is ‘ to feel better ’ and their level of knowledge on types and benefits of mineral supplements is moderate (Chandra, Miller and Willis, 2005).
220.127.116.11 Herb and other botanicals
There are many different herbal and botanical supplements available on the market. Thus, approximately one third of U.S adults reported using botanical supplements (Harris Polls, 1998). In addition, in year 1999 the Chemical Market Reporter revealed that the botanical and herbal market generated approximately $3.9 billion in sales (Anonymous, 1999). A survey shown that about 57.3 percent of adults favourably used herbs in order to treat a specific illnesses (Bardia et al., 2007). According to the survey done by Newberry et al. in 2001 found that 71 of 132 respondents reported they took NVNM health supplements in order to promote good health, prevent disease and to enhance immune system. Most commonly reported used of these NVNM are includes Echinacea, ginseng, St John’s Wort, gingko biloba, ephedra, saw palmetto, chamomile and garlic. From 71 respondents who reported taken NVNM to promote good health about 77.5 percent claimed them to be effective. In addition, 50 respondents reported taken NVNM such as chamomile, gingko biloba, kava kava and St John’s wort in order to relieve depression and anxiety. Fortunately, survey indicated that 43 of 50 respondents perceived them to be effective (Newberry et al., 2001).
18.104.22.168 Amino acid
Our cell is made up from different kind of the building blocks of proteins. This body protein that is called amino acid. Some of the amino acid is been synthesized within the body is called an non-essential amino acid whereas other half cannot be synthesized and must be absorbed and preformed from the gastro-intestinal tracts. This is called essential amino acid which is can be obtained from the food and amino acid supplements. A survey done among college student revealed that 17 out of 272 college students took the putative ergogenic which is commonly considered as amino acid sub-category. The prevalent reason claimed by college students regarding the used of these supplements is to enhance their athletic performance (Newberry et al., 2001).
2.3 Pattern of health supplements used
From NHANES surveys discovered that the most common pattern of supplement use among US population appeared to be the use of single product which is 55 percent. Whereas 66 percent of supplement users took more than one product and only 13 percent took five or more (Sandler et al., 2001). A survey of 21 923 adults residing in the metropolitan boroughs of Bolton and Wigan, UK revealed 35.4 percent took at least one dietary supplement, 72.2 percent were taking one product whereas 27.8 percent taking two or more products. About 12.6 percent reported eating at least five portions of fruits and vegetables per day and 43.5 percent eating at least one portion of oil-rich fish per week. The use of health supplements was positively correlated with the pattern of eating at least five portions of fruits and vegetables per day (adjusted OR 1.41). Correspondingly, consumption of fish-oil supplements was higher among those eating one portion or more of oil-rich fish per week (adjusted OR 1.50) (Harrison et al., 2004).
Besides, a result of the survey also indicated that among women who were reported as regular supplement user, the most usually reported health supplements used were calcium with 60.3 percent user and 20.3 percent for glucosamine. In contrast, most commonly reported health supplements used by men were vitamin C (37.4 percent) and garlic (18.9 percent) (Robson et al., 2008).
2.4 Prevalence use of health supplements
Comparison studies between NHANES 1999-2000 and previous NHANES survey which used same methodology suggested that supplement use has increased (Radimer et al., 2004). A previous study has indicated that most of the supplements have been used in order to promote general health, treat or prevent symptomatic conditions and chronic ailments (Bardia et al., 2007). In 2003 Satia-Abouta et al. study had found that supplements tend to be taken by the people that have been diagnosed with certain medical conditions than others and commented that, although some people take supplements based on efficacy but many do not. A survey result was indicated that supplement use was common among Whites, women, persons with age of 50 years and older and college educated with degree or more (Sheldon & Pelletier, 2003 ; Shi et al., 2005).
In research article by Block and Subar (1990) based on 1987 National Health Interview Survey, they investigate about the used of vitamin and mineral supplements in relation to demographics and amounts of nutrients consumed. This NHIS is a national probability survey among US population. It is the first national studies to address specifically supplement use among Hispanic population. The sample consisted of 22,080 adults of all races aged 18-99 years. A result of the survey revealed that user of vitamin and mineral supplements were slightly more women than were men of the same age and race. Survey shows that among white women within the age ranges 55-64 years, their daily usage are 39.9 percent and 38.4 percent among age ranges 65-74 years. However, among age 75 years and more it is slightly declined (34.9 percent). This indicated that usage pattern tended to increase with age which happened similarly within other sex-age categories. Based on sex-race categories, non-Hispanic whites women show the highest rates of use compared with all other races and Hispanic women show rate intermediate between those of whites and blacks (Blocks & Subar, 1990 ; Jasti, Siega-Riz & Bentley, 2003).
Demographic data regarding income, education, and occupation show that strong socioeconomic influences upon whether individuals take supplements. From the study done by Jong et.al in 2002 revealed that the consumption behaviour towards variety of foods and supplements were associated with demographic and lifestyle characteristics. Result showed that participants in the middle and high education groups were more likely to use supplements containing Echinacea or multivitamin and minerals than individuals with lower education groups. Shi et.al in year 2005 also indicated that the intake of vitamin either in the form of tablets or capsules was significantly common among women and highly educated subjects.
2.4.4 Cultural Factors
A study done by Williams et al. in 1996 indicated that cultural factor also influence in supplement use behavior. Based on ethnographic study of iron and folic acid supplementation among women of reproductive age in developing counteries, they found that cultural factors is plays role in supplement use behaviors (Williams et al., 1996). In addition to demographic determinants of supplement use, understanding of cultural factors also considered as crucial for the success of efforts to encourage supplement use in vulnerable population groups (Jasti, Siega-Riz & Bentley, 2003).
2.5 Attitude and Behaviour Toward Supplementation
Supplement users have been characterized as tend to be healthy people by having a positive attitude towards their health (Dickinson, 2002). In a study done on two-group design of 113 adults in the U.S, the researchers found that participants who have been diagnosed with health problems and experienced on negative effects of their illness showed likeliness to change their attitude towards supplements (McDonald & Nicholson, 2006). However, in a study done by Junko Ishihara and his colleagues revealed something interesting about user’s attitude toward supplementation. Female supplement users who have been influenced by urban lifestyle showed negative lifestyle factors such as frequent eating out and stressful life which later contributed to moderate drinking among them. Those users might be aware of their unhealthy behaviour, hence they intentionally seek to compensate for it with health supplements (Ishihara et al., 2003).
Generally, consumers considered health supplements as a safe product to be taken. However, they might not be aware about a few adverse event that have been reported regarding the unsafe use of these natural products (Ashar & Rowland-Seymour, 2008 ; Palmer et al., 2003). Researchers have indicated that overdoses of Vitamin E consumption may result a prolonged bleeding time due to its effect on intrinsic coagulation pathway (McDonald & Nicholson, 2006 ; Marsh & Coombes, 2006).
2.5.1 Consumer dietary knowledge
Knowledge regarding health supplements also influence the usage of supplements among the consumer. Based on health care professional surveyed revealed that supplement use are varied by profession with the highest frequency among nurses (88 percent), physician assistants and nurse practitioners (84 percent) and lowest among trainees (72 percent) and pharmacists (66 percent) (Jasti et al., 2003). This result indicated that health care professional’s personal habit may affected whether they will recommend a use of health supplement or not (Frank et al., 2000). Futher indication of the supplement use is strongly associated with increased knowledge about nutrition and health (Dickinson, 2002).
From the survey done on 4501 female physicians who participating in the Women Physicians’ Health Study revealed that half of them took a multivitamin-mineral supplement and most of them are those at high risk of getting disease. For example, those who susceptible in getting heart disease tend to consume antioxidant and those with a history of osteoporosis were nearly three times more likely to consume calcium supplement then those with no history of osteoporosis (Dickinson, 2002 ; Frank, Bendich & Denniston, 2000).
A study done by Gardiner and her colleagues between September, 2004 and May, 2005 found that nurses were more preferably to use a multivitamin than other professionals whereas students were more likely to use calcium (Gardiner et al., 2006). Basically, the types of health supplements used by HCP in such no differences compare to those used by the general public (Millen et al., 1987 ; Patterson et al., 1999).This result is consistent with previous surveys of HCPs which indicate a positive correlation between higher use, greater knowledge and increased communications with patients about benefit regarding the use of health supplement (Corbin & Shapiro, 2002 ; Lindquist, Tracy & Savik, 2003 ; Tracy et al., 2005). In case of ordinary users, their knowledge about health supplement also influence the usage of the product. A study done by Peters and his colleagues found that supplements’ user are those people who seek for self-educated approach by consulting a medical doctor and gathering information from credible media sources such as the Internet (Peters et al., 2003).
As one of the developed countries, Malaysians were experienced a nutritional and lifestyle transition due to urbanization, industrialization and globalization. Thus, these rapid alarming trends have lead to the prevalence case of obesity among Malaysians. A study done by National Health and Morbidity Survey (NHMS III) in 2006 was revealed that 14 percents of the adults were obese with the BMI is more than 30 kg/m2. Therefore, this will increased the consumption intake of certain health supplement product that common use in weight loss management program such as Bitter orange (Ashar & Rowland-Seymour, 2008).
In the NHANES 1999-2000, data indicated that those with higher body mass index and current smokers shown as a less likelihood of reporting use of health supplements (Dwyer, Garceau & Evans, 2001 ; Rock et al., 1997). Nonsmokers were more likely to take supplements than were current smokers (Lyle et al., 1998 ; Patterson et al., 1998 ; Subar & Block, 1990). Supplement use also associated with healthy lifestyle, which was similar to the earlier-reported tendency for smoking. For BMI, there was a significant linear decrease of dietary supplement users for higher BMI groups in both sexes (Lyle et al., 1998 ; Newman et al., 1998 ; Subar & Block, 1990). Regarding exercise, there was a significant linear increase in those groups who exercise more frequently. Prior studies had reported alcohol consumption in health supplement users as either having no association or as showing more users among moderate drinkers. Women who drank moderately (once a month to 6 times a week) were most likely to be users (Ishihara et al., 2003).
Study done on a population-based sample of urban Japanese revealed that subjects who experienced more daily stressors (95% CI) are at more higher level of the consumption of vitamin supplements and vitamin enriched drinks compare to those with fewer daily stressors. OR from this study indicated that intake of vitamin supplements by healthy lifestyle’s subjects was related with ‘acts to solve problems’ whereas in subjects with unhealthy lifestyle, reason of intake was associated with daily stressors (Shi et al., 2005).
3.1 Study design
This was a descriptive and cross sectional study Sample size was determined by using a statistical method
By using a multistage random strategy,400 subjects aged between 20 to 69 years were selected from large population of adults in Klang Valley. Klang Valley is urban areas that consists of Gombak, Setapak, Kuala Lumpur, Petaling Jaya, Shah Alam and Klang areas. The ethnicity of the participants were unlimited to specific ethnic group only. Participants were identified at area clinics, shopping complex and park.
A questionnaires was designed to collect information among urban adults regarding their use of health supplements and their attitudes and knowledge toward supplementation of these popular substances. This validated questionnaire was developed from other previous survey and some based on literature review, but we take into account health supplements commonly used in the local setting. This survey questions consisted of four sections. The first section consisted of general demographics information such as gender, race and education. In addition, the participants also will be assessed on their current health status. The second section assessed on the usage of health supplement among those subjects. This part going to find out who took supplements and which ones they took, thus participants will be asked ‘ Do you usually take any of these supplements?’ then subsequent to previous question can be asked. Some products were listed in the questionnaire were the most popular health supplement products in the Malaysia. For completeness, they could add any other health supplement to the list. In the analysis, health supplements were classified into few separate categories such as vitamins, minerals, herbal and other supplements. Question on how they find out about their supplement and how much their are taking each day also possible to be asked. The third session focused on attitudes of participants toward health supplements and the fourth section examined their perception of knowledge concerning the safety of these products. In this questionnaire, the participants will read the questions and statements that have been asked, most of which provided with a ‘true/ false/ don’t know’ or ‘yes/ no/ don’t know’ answer. This questionnaire are provided in the Appendix.
3.4 Statistical Analysis
All statistical analyses were conducted by using SPSS version 17 for Window XP. Descriptive statistics such as frequencies, means, standard deviations (SD), percentage were used to describe all the variables. One-way ANOVA was used to determine differences in continuous variables such as gender, age, education and income. Adjusted odd ratios (OR) of each preditors were calculated using multiple logistic regression in order to examine the effects of demographic and lifestyle on use or non-use of health supplements. Multiple logistic regression analysis also been used to identify the independent contribution of attitudes and knowledge toward the probability of use of health supplements. Futhermore, chi-square test also was used in order to find the correlation between qualitative variables at the 5% significance level. A p-value which less than 0.05 represents a significant difference.
3.5 Ethical approval
Ethical approval for this survey was obtained from the Research Ethics Committee of Research Management Institute, Universiti Teknologi MARA.
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