THE FACTS

Many people think of yogurt as a health food that will aid digestion with probiotics, which are organisms thought to be beneficial for gut bacteria, and support bone health with calcium and Vitamin D, all in a low amount of calories. But is this really true for most common yogurts?

There is merit to this idea. Many yogurts use bacterial cultures of lactic acid- producing Lactobacillus and Streptococcus species. The lactic acid formed by these cultures gives yogurt a tangy taste. In animals and emerging studies with humans, these probiotic gut bacteria can improve lactose intolerance, prevent diarrhea, constipation, colon cancer, inflammatory bowel disease, and even allergies. Thought these outcomes are promising, they do require further research to be validated in supporting human gastrointestinal health. In terms of general nutrition, yogurt contains substantial amounts of protein, potassium, and calcium. It also generally is low in lactose, and can be a way for lactose- intolerant consumers to enjoy the benefits of dairy products.

What many people do not know is that companies look to exploit the benefits of yogurt by marketing it as a health food, particularly to women. Occasioanlly manufacturers must agree to drop  health claims due to criticism that they are exaggerated and unsupported (Cleland, 2011). Some companies claim their products improve gastrointestinal regularity, and can help consumers avoid the cold and flu (Cleland, 2011). Though the effects of probiotics in yogurt are appealing, they are still not quite substantiated to be absolutely true.

Consumers also might not know that many yogurts contain large amounts of added sugar. The USDA averaged that yogurt of the fruit variety has 11.5 g of added sugars per serving and flavored vanilla yogurt has 8.4 grams of added sugar, compared to none in plain yogurt. According to a food nutrient database called iProfile, Dannon Low Fat Strawberry Yogurt with Fruit on the Bottom contains 32 g of sugar, compared to just 12 g of sugar in 8 oz of skim milk. According to the USDA’s program SuperTracker, lowfat yogurt with fruit added averages about 150 calories, 93 of which are empty calories from sugar and a little fat. This shows how many yogurts might not be as nutrient efficient as they are thought to be.

Consumers should be wary of flavored yogurt, as well as yogurt with fruit or sweets included. Instead they can consider purchasing plain yogurts and adding their own fruits and toppings for flavoring. Strained yogurt, otherwise known as Greek yogurt, can be an appropriate option that tends to be higher in protein, and lower in sodium.

THE BOTTOM LINE

Yogurt is a nutrient dense food with the potential to be very beneficial to gastrointestinal health. Consumers should be wary of both the health claims and the added sugar contents of common yogurts, and should look for low sugar, low sodium plain yogurts.

References

Adolfsson, O., Meydani, S.N., & Russell, R.S. (2004, August 8). Yogurt and Gut Function [Fact

    sheet]. Retrieved April 10, 2013, from PubMed.gov website: http://www.ncbi.nlm.nih.gov/pubmed/

    15277142

Cleland, R. (2011, June 24). Dannon Agrees to Drop Exaggerated Health Claims for Activia Yogurt and

    DanActive Dairy Drink. Retrieved April 10, 2013, from Federal Trade Commission website:

    http://ftc.gov/opa/2010/12/dannon.shtm

Smolin, L., & Wiley and Sons, Inc. (2012). iProfile (3rd ed.). Retrieved from

    http://iprofile.wiley.com/iprofile/app/home

USDA Database for the Added Sugars Content of Selected Foods. (2006, February). Retrieved April 10,

    2013, from USDA.gov website: http://www.nal.usda.gov/fnic/foodcomp/Data/add_sug/addsug01.pdf

USDA Food SuperTracker. (n.d.). Retrieved from https://www.supertracker.usda.gov/foodtracker.aspx

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Cara Dooley

UConn Extension Nutrition Intern

Summer 2014

THE FACTS

Many people take daily multivitamins to improve and maintain good health. Vitamin A, found in many dietary supplements, is known to support eye function, tissue growth, as well as bone, reproductive, and immune function.

What many people do not know is Vitamin A comes in many forms. The two main forms consumed by humans are retinol, found in animal sources of food, and beta carotene, an orange plant form. These forms are both metabolized by the body to the active form of vitamin A, retinoic acid.

Many people are also not aware that the recommended daily allowance (RDA) for vitamin A differs according to the form consumed. Food labels list vitamin A in International Units (IUs,) and the RDA use RAE, or Retinol Activity Equivalents for each type of Vitamin A available. For instance, it takes different IU amounts of beta-carotene from food and from dietary supplements to make 1 microgram of retinoic acid, the biologically active form of Vitamin A. So when examining the amount of vitamin A consumed in relation to one’s RDA, it is important to consider where the vitamin A comes from and in what form.

The recommended dietary allowance of vitamin A for an average adult (14 years +) is 700 micrograms RAE (2,300 IUs of retinol, or 4,600 IUs beta carotene from supplements) for females and 900 mircograms RAE (3,000 IUs of retinol, or 6,000 IUs of beta carotene from supplements) for males. Children require even less vitamin A, between 300 and 600 RAE depending on age (1,000- 2,000 IUs retinol, 2,000-4,000 IUs beta carotene from supplements.) Dietary supplements usually supply vitamin A in a combination of the forms of beta-carotene and preformed vitamin A, or retinol. Multivitamin supplements typically contain 2,500 to 10,000 IUs of Vitamin A.

One A Day’s Women’s multivitamin, for instance, contains 4,000 IUs of Vitamin A, with 50 % in the form of beta-carotene. 2,000 IUs of beta-carotene from a dietary supplement, once metabolized to retinoic acid, is equal to 300 RAE of Vitamin A. The remaining 2,000 IUs are found in the form of Vitamin A acetate, a preformed form equal to 600 RAE. So this vitamin totals 900 RAE of vitamin A, exceeding the RDA for women, 700, by 200 micrograms. A person also consumes various amounts of vitamin A in a typical diet, further exceeding the RDA. A ¬Ω cup of carrots contains around 450 micrograms RAE (9,000 IUs beta carotene from food) for instance, which is about half or more than your daily need.

The tolerable upper limit (UL) of Vitamin A for adults is 3,000 micrograms RAE, (10,000 IUs retinol, 20,000 IUs of beta carotene from supplements, or 60,000 IUs beta carotene from food) which will not typically be exceeded by common multivitamins. The UL for children can be as low as 600 micrograms RAE (2,000 IUs retinol, 4,000 IUs beta carotene from supplements.) However, Vitamin A is a fat-soluble vitamin, meaning excess amounts consumed are stored in the body, often in the liver. Hypervitaminosis A or Vitamin A toxicity, is more likely to occur when taking supplements containing preformed vitamin A and beta-carotene than when only consuming vitamin A from the diet. Chronic excessive intake of Vitamin A is associated with dizziness, nausea, skin irritation, joint pain, and, according to some studies, increased risk of lung cancer and cardiovascular disease. Excessive intake of preformed vitamin A is a known teratogen, meaning it can cause birth defects like malformations of the eye, skull, lung and heart.

THE BOTTOM LINE

A diet with variety in fruits and vegetables will typically fulfill an individual’s vitamin A need. Special consideration should be taken when choosing multivitamins with vitamin A, especially for children. When considering supplements, it is wise to reference established values for vitamins and minerals on government (.gov) website databases like the National Institute of Health: Office of Dietary Supplements.

References:

National Institute of Health. "Dietary Supplement Fact Sheet: Vitamin A." Office of Dietary

    Supplements. Office of Dietary Supplements, 25 July 2012. Web. 26 Mar. 2013.

    <http://ods.od.nih.gov/factsheets/VitaminA-HealthProfessional/#h2>.

"One a Day Women's: Overview." One a Day. N.p., 2012. Web. 26 Mar. 2013. <http://oneaday.com/

    womens.html>.

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Cara Dooley

UConn Extension Nutrition Intern

Summer 2014

As it turns out, the majority of individuals can and usually do meet their dietary recommendations for each vitamin and mineral without supplementation through their daily diet. There are only some groups of the population who benefit from taking multivitamins, and some nutrients that are beneficial when supplemented. Also, the nature of most vitamins and minerals renders supplementation, especially in multivitamin form, somewhat inefficient. Consumers may want to consider these facts when choosing supplements.

Generally, the discovery of most vitamins and essential minerals involved a large population presenting the same sickness, and an investigation into what these people had in common. What would be found in common is that their diets universally lack a certain group of food, and these foods contained one substance. When introduced to foods with this substance, the people would no longer be sick. These substances were then called vitamins, and without them, people develop problems due to deficiency.

Vitamin and mineral deficiencies are rare in today’s society, with the exception of iron deficiency anemia in women. Most deficiencies have been addressed over the years through fortification of foods and increased diet variety (Smolin, 2013.) Most grains, for instance, breakfast cereals in particular, are now are fortified (if whole grains) or enriched (if processed) to contain substantial levels of B vitamins like folate, thiamin, riboflavin, niacin and iron. A healthy adult or child of the general population can get all of his or her dietary recommendations for each nutrient through the diet without supplementation and without too much effort. The essential nutrients are consumed in adequate amounts in a normal diet.

A supplement like a multivitamin provides all or most of the discreet compounds that prevent deficiencies. However, it is important to recognize that just because vitamin A prevents a certain type of night blindness; taking vitamin A in excess does not boost or improve eye function. In fact, there is still much to be known about the short and long term effects of taking vitamins and minerals in excess.

Additionally, dietary supplements are not regulated or tested by the FDA. The FDA generally does not verify the heath claims put of dietary supplement labels, nor does it test the amount of each nutrient and its effect (Smolin, 2013). Therefore, customers should be wary of health claims as well as labeled amounts of supplements given.  

So can anyone benefit from multivitamins?

There are groups of people that can benefit greatly from a multivitamin. These groups are either nutrient deficient or at risk of nutrient deficiency. For example, pregnant women are advised to take multivitamins and supplements because they are especially prone to certain deficiencies and need special amounts of certain nutrients like folic acid to prevent fetal abnormalities (Judith, 2012). The elderly can also benefit from taking certain multivitamins because their digestive tracts may not be able to absorb certain nutrients efficiently (Judith, 2012). Those following the vegan diet or other restrictive diets may benefit from a multivitamin as well. Vegetarians, however, are not included in this group, as their diets can meet all of an individual’s nutrient needs if followed correctly (Judith, 2012). There are also a variety of medical conditions that may prevent a person from being able to consume all the nutrients they need for a variety of reasons. Healthy children and adults however, generally do not need to supplement their diet with multivitamins.

Is there any nutrient generally appropriate to supplement?

There are nutrients that the general population is lacking and are recommended in the form of a supplement. Vitamin D supplements are the only recommended supplement to all age groups, 600 IUS per day, because Americans, on average, spend a lot of time indoors or live in latitudinal areas where they cannot receive substantial sunlight to manufacture enough vitamin D precursors (Judith, 2013). This is the only nutrient many Americans physically cannot receive in adequate amounts in their diet. Nutrients that are also acceptable to supplement are Omega-3 fatty acid, folic acid, EPA and DHA (commonly found in fish oil), vitamin D, and iron if discussed with a doctor (Judith, 2013). These however, are best supplemented individually, not in a multivitamin.

Multivitamins, though packed with vitamin and minerals, are often ineffectively absorbed into the body as well as inefficiently stored. Often, supplements taken by mouth are not readily absorbed and taken into the body, and can even hinder the absorption of other essential nutrients. Iron, for instance, is a compound that not only is poorly absorbed and known to cause stomach upset, but it also binds to other nutrients like Calcium, Vitamin D and Zinc and prevents their absorption as well (Dietary Supplement Fact Sheet, 2007). For this reason iron is not recommended to be taken with meals, or in multivitamins with other nutrients (Dietary Supplement Fact Sheet, 2007). Also, much of what is packaged and labeled is readily excreted in the urine. B vitamins and vitamin C, are all water soluble in nature. This means that excess levels are not stored in the body, rather, they are excreted in the urine without use (Smolin, 2013). Many vitamins are fat soluble, meaning they are stored in the body, and not excreted over time. Because they are stored, these vitamins’ requirements do not need to be filled daily and deficiencies are rare (Smolin, 2012).

THE BOTTOM LINE:

Though there are some exceptions, for most of the general population, the cheapest, safest way to receive all the essential nutrients is through the diet.

References

Dietary Supplement Fact Sheet: Iron [Fact sheet]. (2007, August 24). Retrieved April 17, 2013,

from National Institue of Health Office of Dietary Supplements website: http://ods.od.nih.gov/factsheets/Iron-HealthProfessional/

Judith, B. E. (2011). Nutrition Through the Life Cycle (4th ed.). Belmont, CA: Wadsworth

CENGAGE Learning.

National Institute of Medicine, F. A. N. B. (2010). Dietary Reference Intakes (DRIs): Estimated

Average Requirements. In National Academy of Sciences. Retrieved April 15, 2013, from  USDA Website: http://www.iom.edu/Activities/Nutrition/SummaryDRIs/~/media/Files/Activity%20Files/Nutrition/DRIs/5_Summary%20Table%20Tables%201-4.pdf

Smolin, L. A., & Grosvenor, M. B. (2012). iProfile (3rd ed.). Retrieved from

    http://iprofile.wiley.com/iprofile/app/

Smolin, L. A., & Grosvenor, M. B. (2013). Nutrition: Science and Applications (3rd ed.).

Somerset, NJ: Wiley and Sons.

Cara Dooley

UConn Extension Nutrition Intern

Summer 2014