Do Multivitamins Work and Are They Worth It?

Multivitamins are the most commonly used supplements worldwide. They can be useful in helping you maintain the recommended daily intake of essential nutrients. Let’s take a look at what they contain, when they are particularly important for your health and help you make a decision about whether they are an important addition to your lifestyle.

What is in a Multivitamin?

Multivitamins are essentially dietary supplements, which are usually available in the form of tablets, capsules, liquids, pastilles, powders, and even injections. These supplements contain a combination of vitamins, minerals and other nutritional elements which are involved in the regulation of various body functions.

Common multivitamin supplements contain at least three vitamins and minerals and generally do not include drugs, hormones, and herbs. Moreover, the vitamins and minerals which are usually included in these supplements are carefully dosed so that they do not exceed the required daily dose. The vitamins that are commonly included in standard multivitamin supplements include Vitamin A, B1, B2. B3, B5, B6, B7, B9, B12, C, D2, D3, E, and K. While the minerals which are commonly incorporated include Iron, Manganese, Magnesium, Calcium, Potassium, and Iodine.

Water-soluble vitamins are able to be excreted out via the urine and an overdose of these vitamins does not usually result in toxicity in the body. Fat-soluble vitamins are not easily excreted out of the body, and their consumption above the upper limit may lead to toxicity. (1)

This is why the Australian Government regulates all vitamin supplements available in the market by conducting core product assessments to make sure these supplements meet the following criteria.

• The vitamins and minerals included in a supplement should meet the pre-approved list maintained by the Theurapeutic Goods Administration, based on quality and safety.
• The brands selling the supplements in the Australian market cannot make claims about serious and life-threatening conditions.
• The manufacture of multivitamins must be done in a certified facility that meets the standards for safety and quality.
• The sponsor of the product must hold evidence that their product does what they say it does.

Who May Be At Risk Of A Nutrient Deficiency?

Elderly

As individuals age, the body undergoes certain changes, some of which may lead to varying degrees of nutritional deficiency. Adequate nutrition is important for older individuals, as nutrient deficiencies have the potential to affect quality of life, along with mental, physical and social health. Moreover, these nutritional deficiencies may also predispose elderly individuals to chronic health conditions that may further accelerate their aging process and possibly lead to early mortality(2). Vitamin B12 absorption can decrease with age and older adults need more calcium and Vitamin D. Multivitamins may improve memory and mood and may slow the progression of chronic disease.

Pregnant Females

The body of an expecting female is providing for two instead of one. Hence it has a greater nutritional requirement as compared to the body of a woman who is not expecting. The vitamins and minerals which are required by expecting females in higher quantities include Vitamin A, Vitamin D, Vitamin E, Vitamin B12, Vitamin B6, Vitamin C, Selenium, Copper, Zinc, Folic Acid, and Iron. This is because a deficiency of these multivitamins may lead to developmental abnormalities in the growing baby and are required for proper growth and development. Folate is a B-group vitamin essential for the healthy development of the baby in pregnancy. Deficiency can lead to neural tube defects. Folate requirements are increased substantially in pregnancy and women should aim to intake at lease 600mg from their daily diet. In addition, pregnant women should take a daily supplement containing at least 0.5mg of folic acid. (3)

Malabsorption Conditions

Certain conditions like Coeliac Disease, Crohn’s Disease, and Pancreatitis may lead to varying degrees of malabsorption of nutrients, which leads to deficiency. This is because malabsorption prevents the absorption of the nutrients acquired through food due to certain defects in the small intestine, where most nutritional absorption occurs.  (4)

Consumption of Certain Medications

Using certain medications over the long term can also lead to nutritional deficiencies in the body due to the nutrient-drug interactions. These nutritional deficiencies may not develop immediately after starting a new medication but may develop over months to years. These drugs cause nutritional deficiencies by affecting the food intake of an individual, the digestion of the food in the body, its absorption in the intestine, and even its distribution throughout the body after being absorbed into the bloodstream. Moreover, certain drugs may also prevent the conversion of certain vitamins to their active forms and hence affecting their role in bodily functions, leaving a negative impact(5). For example, common oral contraceptives can lead to a defiency in folic acid, magnesium and vitamin B5.

Do Multivitamins Work?

Studies have shown that a well balanced diet contains an adequate level of nutrients for the maintenance of normal body functions. Moreover, it is also shown that consumption of a slightly higher dose of nutrients than the recommended minimum daily dose can also provide the individual with extra health benefits.

While consumption of multivitamins is effective for the prevention of nutritional deficiencies in the body, it is not effective for the prevention of chronic and life-threatening diseases like cancer and cardiovascular conditions.

Hence, whether or not multivitamins are effective depends on the reason why the individual is taking them. While multivitamins may be important for individuals who are at a greater chance of nutritional deficiencies like expecting mothers, older adults, and individuals with malabsorptive conditions, they may not have a significant clinical effect for the general population (6).

Are Multivitamins Worth It?

Multivitamins should not be considered as a shortcut to the prevention of chronic conditions or to better health. They are a form of dietary supplement ideal for those who are at a greater risk for nutritional deficiencies. Most people receive an adequate intake of essential nutrients from a balanced diet.

Hence, taking a multivitamin may be worth it if they are consumed in the right way, for the right reason under the guidance of a health professional.

Should I Take A Multivitamin Everyday?

It has been reported that at least one-third of adults take at least one supplement of multivitamins per day. While they may benefit individuals who actually require multivitamin supplementation to overcome nutritional deficiences, they may not have a significant clinical benefit for the general population. (7)

Hence, in order to decide whether you should consume a multivitamin every day or not, you should consider the following points:

• Consult a Doctor: Have a thorough discussion with your doctor and consult whether you really require a multivitamin supplement. This is accompanied by a general checkup and may require blood tests as well.
• Record what you eat in a day: If you believe you are not getting enough nutrients due to your eating habits, start recording what you eat throughout the day and then evaluate whether anything is lacking in your daily diet. Consider talking to a dietician.

References:

1. Menon AS, Narula AS, Mathur AG. Multivitamins : Use or Misuse?. Med J Armed Forces India. 2008;64(3):263-267. doi:10.1016/S0377-1237(08)80111-6
2. Kaur D, Rasane P, Singh J, et al. Nutritional Interventions for Elderly and Considerations for the Development of Geriatric Foods. Curr Aging Sci. 2019;12(1):15-27. doi:10.2174/1874609812666190521110548
3. Gernand AD, Schulze KJ, Stewart CP, West KP Jr, Christian P. Micronutrient deficiencies in pregnancy worldwide: health effects and prevention. Nat Rev Endocrinol. 2016;12(5):274-289. doi:10.1038/nrendo.2016.37
4. Zuvarox T, Belletieri C. Malabsorption Syndromes. [Updated 2021 Jul 30]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK553106/
5. Mohn ES, Kern HJ, Saltzman E, Mitmesser SH, McKay DL. Evidence of Drug-Nutrient Interactions with Chronic Use of Commonly Prescribed Medications: An Update. Pharmaceutics. 2018;10(1):36. Published 2018 Mar 20. doi:10.3390/pharmaceutics10010036
6. Blumberg JB, Cena H, Barr SI, Biesalski HK, Dagach RU, Delaney B, Frei B, Moreno González MI, Hwalla N, Lategan-Potgieter R, McNulty H, van der Pols JC, Winichagoon P, Li D. The Use of Multivitamin/Multimineral Supplements: A Modified Delphi Consensus Panel Report. Clin Ther. 2018 Apr;40(4):640-657. doi: 10.1016/j.clinthera.2018.02.014. Epub 2018 Mar 21. PMID: 29573851.
7. Millen AE, Dodd KW, Subar AF. Use of vitamin, mineral, nonvitamin, and nonmineral supplements in the United States: The 1987, 1992, and 2000 National Health Interview Survey results. J Am Diet Assoc. 2004 Jun;104(6):942-50. doi: 10.1016/j.jada.2004.03.022. PMID: 15175592.
   

   About the Author

   • 
   • Dr Ganesh Naidoo

     BSc(biomed), MBBS, FRACGP is an Australian General Practitioner. He has significant clinical experience in multiple regions of Australia and has a passion for health transformation to improve clinical outcomes for all patients.