Test your knowledge
Take our supplement quiz, and test your knowledge of popular vitamins, minerals, and herbs.
Vitamins, minerals, and herbs line the shelves of your local natural health store. Take our true or false quiz and test your knowledge of these popular supplements.
Vitamin C can improve mood and relieve fatigue. True or false?
True: People who suffer from a vitamin C deficiency may feel depressed or tired. Studies have shown that supplementation with vitamin C daily can improve mood.
Researchers studied whether supplementing acutely hospitalized patients with vitamins C and D could improve their mood. Patients received either 500 mg of vitamin C twice daily or 1,000 IU of vitamin D twice a day. The patients who took vitamin C experienced a 34 percent decrease in mood disturbances, an effect not seen in those who took vitamin D.
Supplementing with 500 mg of vitamin C a day has been shown to be safe, with 2,000 mg the safe upper limit. Vitamin C may play an important role in strengthening the immune system, reducing stroke risk and inflammation, and lowering the risk of cancer and cardiovascular disease.
Pregnant women should begin taking prenatal vitamins after they find out they’re pregnant. True or false?
False: Women who are trying to get pregnant should start taking prenatal vitamins three months before they hope to conceive, and continue to take them throughout pregnancy. Your health care practitioner may recommend them during breastfeeding too.
Prenatal vitamins contain extra folic acid, iron, and calcium compared to regular multivitamins. The developing fetus requires folic acid to prevent neural tube defects (serious problems with the brain and spinal cord, such as spina bifida). The extra iron helps prevent anemia and helps build blood and muscle cells in mom and baby. Prenatal vitamins may also reduce the risk of low birth weight.
Take these supplements with water or juice, not milk. To minimize the possibility of nausea, try taking them at night or with a snack, or chew sugarless gum after taking them.
We absorb less calcium as we get older. True or false?
True: The amount of calcium our body absorbs depends on our age and bodily needs. As infants and children, our net calcium absorption is as much as 60 percent. At this stage of our development, our body requires a lot of calcium to build strong bones.
As we age our net calcium absorption decreases. By the time we’re adults, it’s down to 15 to 20 percent. Pregnant women absorb more as their need for calcium increases during pregnancy. Women older than 50 and men and women older than 70 require more calcium (see below).
The percentage of calcium our body absorbs depends on how much elemental calcium we take in. The more calcium we take, the less calcium we absorb. Optimal absorption occurs at doses of 500 mg or less. So, if your calcium requirement is 1,000 mg a day, split the dose and take 500 mg twice each day.
Note that calcium can interact with many medications, such as some types of antibiotics and blood pressure medications. Check with your health care practitioner if you take any medications.
Daily calcium requirements
Follow these guidelines to ensure you take the optimal amount of calcium.
|Age ||Recommended dietary allowance (RDA) per day||Tolerable upper intake level (UL) per day|
|0 to 6 months||200 mg adequate intake||1,000 mg|
|7 to 12 months||260 mg adequate intake||1,500 mg|
|1 to 3 years ||700 mg ||2,500 mg|
|4 to 8 years||1,000 mg ||2,500 mg|
|9 to 18 years||1,300 mg||3,000 mg|
|19 to 50 years||1,000 mg||2,500 mg|
|Pregnant and breastfeeding women|
|14 to 18 years |
19 to 50 years
|1,300 mg |
|3,000 mg |
|51 to 70 years|
|1,000 mg |
|2,000 mg |
|All adults over 70 years||1,200 mg||2,000 mg|
Women younger than 75 who get an adequate amount of vitamin D in their diet can lower their chance of developing age-related macular degeneration. True or false?
True: Research shows that women in this age group whose blood serum contained the highest levels of vitamin D decreased their risk of getting macular degeneration by 59 percent, compared to women with the lowest levels.
Age-related macular degeneration is a chronic, late-onset disease that affects the macula, or the central area of the retina, responsible for clear, focused vision. It is the major cause of irreversible vision loss in older people.
Among the best food sources of vitamin D consumed by women involved in the study were milk, fish, and fortified cereal. Other excellent sources of vitamin D are salmon, sardines, fish oils, yogourt, and eggs.
More research is needed to understand how vitamin D works with genetic and lifestyle factors to lower the risk of macular degeneration.
St. John’s wort is as effective at relieving depression as prescription antidepressant medication. True or false?
True: St. John’s wort has been used to treat anxiety and depression for centuries. Much research has been carried out into its effectiveness at treating depression.
The US National Center for Complementary and Alternative Medicine co-funded a study that found St. John’s wort was no more effective than placebo when used to treat major depression of moderate severity.
However, other research shows that it can be used effectively to treat mild to moderate depression. A double-blind, randomized, multi-centre clinical trial studied 332 patients who suffered from mild to moderate major depression.
Patients were given either 600 mg of St. John’s wort (Hypericum perforatum) a day or 1,200 mg a day in two doses, or placebo. St. John’s wort was found to be safe and more effective than placebo for treating mild to moderate major depression.
A 2009 meta-review of 29 studies came to the conclusion that St. John’s wort was as effective for treating mild to moderate depression as standard antidepressants, with fewer side effects.
Consult a health care practitioner before taking St. John’s wort to determine the correct dosage. It also may interact with medication including birth control pills, blood thinners, and antidepressants.
It’s safe to take supplements while taking medication. True or false?
True and false: Usually it is safe, but some supplements can interact with some over-the-counter medicines such as Aspirin, as well as a wide variety of prescription medicines including blood thinners and blood pressure medication. Some supplements may contribute to complications, such as bleeding or high blood pressure, in patients undergoing surgery.
People with chronic health problems are at greatest risk for an interaction between a supplement and a medication. Yet a 2008 study showed that less than 51 percent of people with a chronic condition let their conventional health care practitioners know that they were taking herbs or supplements.
It’s always advisable to let your health care practitioner know if you’re taking any type of herb or supplement, and better yet to consult him or her before adding supplements to your daily regimen if you have any type of health issue.