Nutrition Action Healthletter
September 1999 — U.S. Edition


Don’t get nervous.

No one (but you) has to know how you scored on this tough test. And we mean tough. It’s not so much a test as a way to help pull together all that you’ve heard about vitamins, etc. If you get discouraged, cheat. Feel free to look at the answers as you read the questions. • You may wonder why so many questions ask which vitamin or mineral doesn’t prevent or cause some health problem. That way, instead of finding just one thing that works, you learn about three or four that do (and one that doesn’t). Each question has only one answer.


What to Take

Getting enough vitamins, minerals, fiber, and other phytochemicals isn’t as hard as it may seem.


Eat a healthy diet. Start with a diet built around fruits and vegetables (eight to ten servings a day); whole-grain breads and cereals; beans; low-fat poultry and meat; non-fried fish; and low-fat milk, cheese, and yogurt.


Take a multi. For insurance, take an ordinary multivitamin-and-mineral supplement like Centrum (or Centrum Silver) or a store-brand knock-off with the same ingredients.


Count up your calcium. Do you eat three (if you're under 50) or four (if you’re over 50) servings a day of (low-fat) milk, yogurt, or cheese? If not, take a supplement (like Tums or a store-brand calcium carbonate) with 300 mg of calcium a day for every dairy product you miss. Your goal: 1,000 mg a day (if you’re 19 to 50) or 1,200 mg a day (if you’re over 50).


Consider taking extra E. Studies suggest that 50 IU a day may cut the risk of prostate cancer, 100 IU a day may lower the risk of heart disease, and 200 to 400 IU a day may boost the immune systems of older people or help curb muscle damage that occurs when they exercise. You can’t get those levels from food. The evidence isn’t strong enough to say that vitamin E works, but it’s a good bet.


Consider selenium. In 1996, researchers reported that people who took 200 mcg of selenium a day had a lower risk of prostate, lung, and colon cancer. Until ongoing studies confirm those results, it’s too early to say that selenium prevents cancer. But it’s worth considering a supplement.

1.  The B-vitamin folate may help prevent all but one of the following. Which one?
  a.  heart disease
b.  stroke
c.  prostate cancer
d.  colon cancer
e.  birth defects
2.  If you are older than 55, which is the best source of vitamin B-12?
  a.  milk
b.  poultry
c.  eggs
d.  green leafy vegetables
e.  a vitamin supplement
3.  All but one of the following can be a sign of vitamin B-12 deficiency. Which one isn’t?
  a.  memory loss
b.  excessive thirst
c.  mental confusion
d.  blurred vision
e.  tingling in the feet
4.  Which B-vitamin can cause nerve damage if taken in high doses?
  a.  thiamin (B-1)
b.  riboflavin (B-2)
c.  niacin (B-3)
d.  pyridoxine (B-6)
5.  All but one of the following may lower the risk of heart disease. Which one doesn’t?
  a.  vitamin B-2
b.  vitamin B-6
c.  vitamin E
d.  folate
e.  fiber-rich foods
Vitamin D & Calcium
6.  Getting enough calcium may help cut the risk of which cancer?
  a.  breast cancer
b.  bladder cancer
c.  colon cancer
d.  prostate cancer
7.  People over age 50 should get 1,200 mg of calcium a day. That’s the amount in all but one of the following. Which one doesn’t have that much?
  a.  four cups of milk
b.  six ounces of cheddar cheese
c.  nine cups of cottage cheese
d.  five cups of cooked broccoli
e.  four cups of calcium-fortified orange juice
8.  What’s the maximum daily dose of calcium that’s considered safe?
  a.  1,500 mg
b.  2,500 mg
c.  3,500 mg
d.  4,500 mg
e.  no limit
9.  Vitamin D may help prevent or treat all but one of the following. Which one?
  a.  high blood pressure
b.  hip fractures
c.  osteoarthritis
d.  steoporosis
10.  If you’re middle-aged, all but one of the following can supply a day’s worth of vitamin D. Which one can’t?
  a.  a multivitamin
b.  a highly fortified cereal like Product 19 or Total
c.  four glasses of milk
d.  exposing your hands, face, and arms to the sun for five to ten minutes two or three times a week in the summer months (anywhere) or at any time of the year (in the South)
Other Vitamins & Minerals
11.  All but one of the following help prevent high blood pressure. Which one doesn’t?
  a.  limiting sodium (salt)
b.  consuming enough potassium
c.  getting enough vitamin E
d.  eating enough fruits and vegetables
e.  getting enough exercise
12.  All but one of these foods are good sources of potassium. Which one isn’t?
  a.  bananas
b.  milk
c.  dry beans
d.  rye bread
e.  chicken
13.  Though the evidence is sometimes shaky, too much iron can raise the risk of all but one of the following. Which one?
  a.  memory loss
b.  heart disease
c.  cancer
d.  liver damage
14.  Evidence suggests that all but one of the following lower your risk of diabetes. Which one doesn’t?
  a.  staying lean
b.  eating fiber-rich foods
c.  eating enough magnesium
d.  eating enough potassium
e.  getting enough exercise
15.  Evidence indicates that all but one of the following may cut the risk of prostate cancer. Which one doesn’t?
  a.  magnesium
b.  lycopene
c.  selenium
d.  vitamin E
e.  eating less meat
16.  Which is the best source of vitamin E?
  a.  whole-wheat bread
b.  olive oil
c.  broccoli
d.  almonds
e.  beans
17.  Which can impair the immune system if taken in large doses?
  a.  copper
b.  iron
c.  zinc
d.  vitamin A
18.  According to the latest estimates, how much vitamin C do most people need each day?
  a.  60 mg
b.  200 mg
c.  500 mg
d.  1,000 mg
e.  5,000 mg
19.  All but one of the following appear to help strengthen bones. Which one doesn’t?
  a.  vitamin D
b.  vitamin K
c.  vitamin E
d.  fluoride
20.  A deficiency of which nutrient can’t be detected by a blood test?
  a.  vitamin B-12
b.  vitamin D
c.  zinc
d.  iron
21.  Which is the best source of selenium?
  a.  whole-wheat bread
b.  spinach
c.  fortified breakfast cereal
d.  a supplement
22.  High doses of vitamin A or its precursor (beta-carotene) may raise the risk of all but one of the following. Which one?
  a.  colon cancer
b.  lung cancer
c.  liver damage
d.  birth defects
23.  Which one of the following appears to curb the muscle damage caused by exercise in people older than 55?
  a.  vitamin A
b.  vitamin B-1
c.  vitamin C
d.  vitamin E
24.  All but one of these foods are good sources of magnesium. Which one isn’t?
  a.  bran cereal
b.  cantaloupe
c.  spinach
d.  black beans
e.  yogurt
25.  Which food may protect your eyes as you age?
  a.  collard greens
b.  soybeans
c.  purple grape juice
d.  carrots
26.  Which supplement is most likely to do what its proponents claim it does?
  a.  echinacea
b.  lecithin
c.  saw palmetto
d.  DHEA
27.  Which supplement is least likely to do what its proponents claim it does?
  a.  glucosamine
b.  St. John’s wort
c.  kava kava
d.  ginseng
28.  All but one of the following are rich sources of omega-3 fats. Which one is only a minor source?
  a.  cod
b.  sardines
c.  rainbow trout
d.  salmon
29.  Adverse effects or contaminants have been reported for all but one of the following. Which one?
  a.  ephedra
b.  DHEA
c.  5-HTP
d.  chondroitin
30.  Which one of the following is most likely to improve your memory?
  a.  vitamin E
b.  phosphatidyl serine
c.  lecithin
d.  ginkgo biloba
1.   c.   prostate cancer
Women who could become pregnant should take a multivitamin with 400 mcg, the Daily Value for folate. That amount helps prevent neural tube birth defects. Though more studies are needed, the same level also appears to cut the risk of heart disease, stroke, and colon cancer. [back]

2.   e.   a vitamin supplement
In younger people, all but the vegetables would be a good source of B-12 (which is only found in animal foods). But if you’re over 55, your stomach might not produce enough acid to extract the B-12 from food. To play it safe, take a daily dose of 25 mcg, the amount in many supplements for seniors. [back]

3.   b.   excessive thirst
Vitamin B-12 deficiency can cause irreversible nerve damage. If you have any of the symptoms (other than excessive thirst), get your B-12 blood levels checked. Anemia can also be a sign of B-12 deficiency, but you can get nerve damage without anemia. (Excessive thirst could be a sign of diabetes.) [back]

4.   d.   pyridoxine (B-6)
The B-vitamins—like other water-soluble nutrients—are usually safe at high doses. B-6 is the exception. The Tolerable Upper Intake Level (UL) was set at 100 mg because higher daily doses can cause a (reversible) nerve toxicity that leads to difficulty walking, clumsiness, numbness, or burning, shooting, or tingling pains. The Daily Value for B-6 is only 2 mg. [back]

5.   a.   vitamin B-2
People who consume more vitamin B-6 (about 4.6 mg a day), folate (at least 400 mcg a day), or vitamin E (at least 100 IU a day) have a lower risk of heart attacks. Vitamin B-6 and folate may protect the heart by lowering blood levels of homocysteine. None of the research is definitive, though. Clear answers about vitamin E may come from clinical trials that are under way to see if it can prevent heart attacks. [back]

6.   c.   colon cancer
In a study of people who already had precancerous colon polyps, taking 1,200 mg of calcium a day cut the risk of new polyps by 24 percent. However, preliminary evidence suggests that men who consumed 2,000 mg of calcium a day—from food or supplements—had a higher risk of prostate cancer than men who consumed lower levels. Until we know more, men shouldn’t assume that more calcium is better. [back]

7.   d.   five cups of cooked broccoli
Each cup of cooked broccoli has 70 mg of calcium, so you’d need 17 cups to get a day’s worth of calcium (not that you need to get all your calcium from a single food). Collards (with 230 mg per cup) and cooked frozen kale (with 180 mg per cup) are richer sources. [back]

8.   b.   2,500 mg
In 1997, the National Academy of Sciences set an Upper Tolerable Intake Level (UL) for calcium of 2,500 mg a day. Too much calcium can cause kidney stones, high blood calcium, or impaired absorption of iron, zinc, or magnesium. But 2,500 mg a day isn’t a target. Shoot for 1,000 mg a day if you’re 19 to 50 and 1,200 mg a day if you’re older than 50. [back]

9.   a.   high blood pressure
In a recent study in Boston, half of the women with hip fractures were deficient in vitamin D. So far, only one study has found slower progression of arthritis in people with low D levels. [back]

10.   b.   a highly fortified cereal like Product 19 or Total
Milk—not other dairy products—is one of the few good sources of vitamin D. Even cereals with 100 percent of the Daily Value for other vitamins and minerals don’t supply much D. Experts recommend 200 IU a day if you’re 19 to 50, 400 IU a day if you’re 51 to 70, and 600 IU a day if you’re older than 70. As people age, their skin gets less efficient at making vitamin D when exposed to the sun. You can’t get enough vitamin D from the sun in the winter unless you live in the Southern U.S. [back]

11.   c.   getting enough vitamin E
Avoiding overweight and limiting alcohol (to no more than one drink a day for women; two for men) also keep blood pressure from rising. [back]

12.   d.   rye bread
Fruits and vegetables, especially beans (except green beans), are the best sources. Whole grains have more than their refined cousins (almost all rye breads are refined), but even whole- wheat bread isn’t loaded with potassium. Bran cereals are a better source. Most multivitamin-and-mineral supplements and fortified breakfast cereals don’t supply much potassium. [back]

13.   a.   memory loss
Too little iron can impair memory and learning in adolescent girls (iron deficiency is less common in boys). But too much may raise the risk of cancer and heart disease. About one in 250 Americans has the genes for iron overload, or hemochromatosis, which can damage the liver, heart, brain, pancreas, and other organs. To play it safe, get your blood ferritin checked.
   If you’re male or postmenopausal, look for a multivitamin that supplies no more than 10 mg of iron a day.
   The 18 mg in most multis is the recommended allowance for teenage boys. [back]

14.   d.   eating enough potassium
It’s clear that extra pounds raise the risk of diabetes. Exercise lowers the risk, even if you’re not overweight. The evidence for fiber-rich foods and magnesium, while promising, is shakier. [back]

15.   a.   magnesium
In separate clinical trials, men who took 200 mcg of selenium or 50 IU of vitamin E every day had a lower risk of prostate cancer. Studies are under way to duplicate those results. There are no trials on lycopene or red meat. However, men who eat less red meat—and less animal fat—seem to have a lower risk. Ditto for men who have higher blood levels of lycopene or who eat more lycopene-rich tomato-containing foods, especially cooked foods like tomato sauce. [back]

16.   d.   almonds
Almonds are the best of the bunch, with 11 IU in three tablespoons. But only supplements have the amounts that may help reduce the risk of heart disease (100 IU a day) or prostate cancer (50 IU a day). [back]

17.   c.   zinc
Zinc can impair the immune system at daily doses as low as 50 mg (in addition to the 15 mg in a typical diet). Vitamin A can cause liver damage and possibly birth defects at daily doses of 10,000 IU or more. Vitamin B-6 can cause (reversible) nerve damage at doses of 200 mg or more. [back]

18.   b.   200 mg
The current Daily Value is 60 mg, but some vitamin-C experts think that intakes should be at least 100 mg or, more likely, 200 mg.
   If you eat the eight to ten servings of fruits and vegetables a day that we recommend, you should get at least 200 mg. So far there is no Upper Tolerable Intake Level (UL) for vitamin C. It should be 1,000 mg a day, some argue, because more than that may raise the risk of kidney stones. [back]

19.   c.   vitamin E
Most people know that calcium and vitamin D are crucial for strong bones. But it’s also important to get enough vitamin K. Women should shoot for 65 mcg a day, while men need 80 mcg.
   Green leafy vegetables are the best source. Most people get sufficient fluoride from fluoridated water. [back]

20.   c.   zinc
There is no good way to test for zinc deficiency. Instead, researchers give people more zinc and see if it improves the symptoms of a deficiency—diminished taste, wounds that take long to heal, or recurring infections that don’t clear up easily. As for the other nutrients, it’s worth getting your blood tested for 25-hydroxyvitamin D, serum ferritin (to see if you get too little or too much iron), and vitamin B-12. [back]

21.   d.   a supplement
Seafood is the most reliable food source of selenium. The selenium content of other foods varies depending on where they were grown. If you want to get 200 mcg a day—the amount that may cut the risk of cancer—the safest way is to take a supplement. [back]

22.   a.   colon cancer
As little as 10,000 IU a day of vitamin A may raise the risk of birth defects when taken by pregnant women and may cause liver damage when taken by older people for 10 to 15 years. Beta-carotene doesn’t cause birth defects or liver damage, but two studies found an increased risk of lung cancer in smokers who took 33,000 IU to 50,000 IU (20 mg to 30 mg) of beta-carotene a day for several years. In contrast, beta-carotene-rich foods, like carrots, sweet potatoes, and cantaloupe, are linked to a lower risk of lung cancer. [back]

23.   d.   vitamin E
When sedentary older people were told to exercise for 45 minutes a day, those who were given vitamin E had fewer signs of muscle damage than those who took a placebo. The study used 800 IU a day, but as little as 200 IU to 400 IU may be sufficient. [back]

24.   b.   cantaloupe
Most fruits are not especially rich in magnesium. Nor are most vegetables, except for leafy greens and dry beans. Whole (not refined) grains and milk or yogurt can help you reach 320 mg (women) or 420 mg (men) a day. Most multivitamin-and-mineral supplements and fortified breakfast cereals supply only about 100 mg per serving. [back]

25.   a.   collard greens
Studies suggest that foods rich in lutein, a carotenoid found in green leafy vegetables, may help prevent macular degeneration, the most common cause of blindness in older people. (The macula is the center of the retina.) [back]

26.   c.   saw palmetto
There is consistent evidence that a daily dose of 320 mg of saw palmetto can help men with benign prostatic hypertrophy (enlarged prostates). The evidence for the others is inconclusive. [back]

27.   d.   ginseng
Glucosamine seems to curb arthritis pain, St. John’s wort appears to help one out of two people with clinical depression (whether it “cures the blues” for people who aren’t clinically depressed is untested), and kava kava may help people with clinical anxiety (it’s less certain whether it “relieves daily stress” or helps you relax). So far, there is insufficient evidence that ginseng is good for memory, energy, sexual interest or potency, symptoms of menopause, or the immune system. [back]

28.   a.   cod
In some studies, people who consumed about 1.5 grams of omega-3 fats a week had a lower risk of heart attacks. You can get that much in six ounces of cooked (eight ounces of raw) salmon or rainbow trout or three ounces of canned sardines.
   A six-ounce serving of most other fish, including cod, flounder, tuna, clams, catfish, haddock, perch, and halibut, has between 0.2 and 0.9 grams of omega-3 fats. [back]

29.   d.   chondroitin
Experts are concerned that DHEA may raise testosterone levels, which may increase the risk of prostate cancer. Ephedra has been linked to about three dozen deaths and more than a thousand adverse reactions. And a half dozen samples of 5-HTP tested by the FDA contained a contaminant like the one that caused eosinophilia myalgia—a painful and sometimes disabling muscle disorder—in people who took tainted tryptophan supplements in the late 1980s. [back]

30.   b.   phosphatidyl serine
So far, the evidence is strongest that phosphatidyl serine (PS) can boost memory in healthy people with greater-than-normal, age-related losses. [back]

How’d You Do?
Give yourself one point for each correct answer on this tough quiz.

23 – 30  You rock! Track down an agent to write your own vitamin book.
15 – 22  Not too shabby. You tied with some NAH staff, who shall remain nameless.
8 – 14  Oops. Leave your Nutrition Actions in the bathroom so you can brush up on old issues.
0 – 7  A new subscriber, right? If not, it wouldn’t hurt to get those vitamin B-12 levels checked.
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