Should You Take a Multivitamin Every Day - Essential, Waste or Hoax?
There's an ongoing debate about the merits of taking multivitamins every day. Some people say we need to take them to make sure we are getting our full quota of ALL the vitamins we need to overcome dietary deficiencies. Others say we don't need them because our food provides all our vitamins needs.
The solution to any deficiency is to simply change the diet rather than popping pills. Of course, there are people with special needs or deficiencies for particular vitamins, but people should not take them just in case that have an undiagnosed shortage.
Recent research has shown that people can overdose on vitamins and minerals and this may cause more harm than good. This applies to Vitamin D, calcium and particularly iron.
Many processed foods such as milk, cereals and breads contain boosted amounts of vitamins, and these supplements can quickly add up to an overdose even with normal diets.
It appears that many people are innocent victims of the heavy advertising campaigns that we are all bombarded with, in various media every day.
More than 35% of American adults take multivitamin supplements, and 25% of young children. Use increases as people get older and 40% of adults older than 70 years take these supplements.
Women and people who are better educated, have more income, have healthier diets and lifestyles take more multivitamins regularly.
This article reviews the latest information to help you to decide whether you need daily multivitamin supplements.
A detailed review by the National Institutes of Health (2006) found no conclusive evidence for any benefits from using of multivitamin and mineral supplements in the general population.
The NIH Factsheet provides an update of the latest information. Food is a better source of vitamins because it includes fiber and other ingredients and nutrients such as antioxidants that provide extra health effects.
People who are dieting, or those who have certain diet restrictions such as vegetarians and vegans may need to take vitamins supplements for certain amino acids and fatty acids that are scarce in vegetables and fruit.
However, most people can get all the vitamins they need from food. The chart below shows which foods contain the vitamins you need.
Recommended Daiy Allowance for Vitamins and Minerals and Food Items that Provide Them
|
Vitamin or Mineral
|
Amount
|
Eat this to Get Recommended Daily Allownace
|
|---|---|---|
|
Vitamin A
|
2,310 IU (700 mcg)
|
Two medium baby carrots: 2,758 IU
|
|
Vitamin B1 (Thiamine)
|
1.1 mg
|
One cup oatmeal: 1.2 mg
|
|
Vitamin B2 (Riboflavin)
|
1.1 mg
|
1 cup cottage cheese: 0.4 mg
|
|
3 oz. salmon: 0.4 mg
|
||
|
1 cup cooked spinach: 0.4 mg
|
||
|
Vitamin B3
|
14 mg
|
Half an avocado: 1.3 mg
|
|
(Niacin)
|
2 large carrots 1.4 mg
|
|
|
3 oz. salmon: 8.6 mg
|
||
|
1 medium sweet potato 1.7 mg
|
||
|
1 oz. almonds: 1.1 mg
|
||
|
Vitamin B5
|
5 mg
|
1.5 cups oatmeal: 1.4 mg
|
|
(Pantothenic acid)
|
1 cup plain nonfat yogurt 1.6 mg
|
|
|
3 oz. roasted chicken0.9 mg
|
||
|
1 cup brown rice0.6 mg
|
||
|
1 small sweet potato: 0.5 mg
|
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|
Vitamin B6
|
1.3 mg
|
3 oz. salmon: 0.8 mg
|
|
(Pyridoxine)
|
1 cup long grain brown rice: 0.3 mg
|
|
|
1 cup raw broccoli: 0.2 mg
|
||
|
Vitamin B7
|
30 mcg
|
Our bodies recycle a significant amount of biotin so deficiency is rare.
|
|
(Biotin or Vitamin H)
|
||
|
Vitamin B9
|
400 mcg
|
One cup cooked spinach: 263 mcg
|
|
(Folic Acid)
|
1/2 cup kidney beans: 115 mcg
|
|
|
1 cup fresh orange juice: 75 mcg
|
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|
Vitamin B12 (Cobalamin)
|
2.4 mcg
|
1 oz. cheddar cheese: 0.2 mcg
|
|
3 oz. roasted chicken: 0.3 mcg
|
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|
One cup plain nonfat yogurt 1.5 mcg
|
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|
1 tbsp nutritional yeast: 4 mcg
|
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|
Vitamin C
|
75 mg
|
1 large orange: 97.9 mg
|
|
Vitamin D
|
600 IU (15 mcg)
|
1 cup milk: 100 IU
|
|
1 cup Silk plain soymilk: 119 IU
|
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|
3 oz. mackerel: 388 IU
|
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|
Vitamin E
|
22.5 IU (15 mg)
|
One cup cooked spinach: 3.7 mg
|
|
2 tbsp. olive oil 3.8 mg
|
||
|
1 cup quinoa 1.2 mg
|
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|
1 oz. almonds 7.3 mg
|
||
|
Calcium
|
1,000 mg
|
1 cup plain nonfat yogurt 488 mg
|
|
1 cup Silk plain soymilk: 299 mg
|
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|
1 cup cooked spinach: 245 mg
|
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|
Iron
|
18 mg
|
1 cup cooked spinach 6.4 mg
|
|
1 cup oatmeal: 3.4 mg
|
||
|
1/2 cup lentils: 3.3 mg
|
||
|
1 cup barley: 2.1 mg
|
||
|
2 beets0.8 mg
|
||
|
1 medium baked potato with skin 1.9 mg
|
||
|
Potassium
|
4,700 mg
|
1 large banana 487 mg
|
|
2 large kiwis 568 mg
|
||
|
1 cup plain nonfat yogurt 625 mg
|
||
|
1 cup fresh orange juice: 496 mg
|
||
|
1 medium russet potato 952 mg
|
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|
1 cup diced cantaloupe: 417 mg
|
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|
1/2 cup edamame beans 338 mg
|
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|
1 cup cooked Swiss chard 961 mg
|
People Who May Require Multivitamin Supplements
The recommended daily allowance of various vitamins and minerals for men, women and children at various ages are shown in the table below.
The groups who generally require additional vitamin supplements or fortified foods are:
- Women who are trying to start a family should get at least 400 mcg per day of folic acid from fortified foods or take folate dietary supplements to eliminate the risk of birth defects in the brain and spine in their newborn babies.
- Pregnant women should ensure they get enough iron by following the recommendations of their doctor or other health care provider.
- Babies that are completely or partially breastfed should get 400 IU per day of vitamin D supplements. The same applies to non-breastfed infants, but milk formula and various milks are often fortified with vitamin D.
- Post-menopausal women should ensure that they get enough vitamin D and calcium to maintain bone strength and reduce the risk of osteoporosis .
- Mean and women over 50 years of age should ensure that they are getting enough vitamin B12 from dietary supplements or fortified foods.
Risks and Harmful Effects of Overdosing on Multivitamins and Minerals
Taking a basic multivitamin supplement is generally unlikely to pose any risks to your health. But if you consume foods and drinks fortified with added vitamins (such as cereals, milk or fruit juices) your total intake could exceed the recommendations of your daily allowance. (See the table below)
Of particular concern is vitamin A, beta-carotene (which is a pre-cursor to vitamin A) and iron in the multivitamin and food. If you regularly take megadoses of vitamins and minerals you may experience side-effects. For example, too much zinc or vitamin C can cause nausea, stomach cramps and diarrhea. Too much selenium is known to cause hair loss, stomach upsets, fatigue, and even mild damage to nerves.
Signs of an overdose of vitamin A may include blurred vision, nausea and dizziness. Adults who take more than 4,000 international units (IUs) of Vitamin A, a day over long periods of time may get kidney stones and heart problems. Similar problems may develop if calcium intake exceeds the upper limit of about 2,000-2,500 milligrams daily.
There is growing concern about problems with foliate intakes exceeding 1,000 micrograms per day. Taking too much iron can cause iron overload leading to many health problems. The excess iron can gradually builds up in tissues and organs. Early warning signs include fatigue, abdominal pain, irritability, weakness, weight loss, changes in skin color, pain in the joints, depression and blood disorders. The build up of excess iron in the body can damage the organs including the heart.
Can you Lower the Risk of Cancer by Consuming a Multivitamin Supplement Every Day?
On the other side of the debate, research findings keep surfacing that suggest there may be long term benefits of taking multivitamins regularly. One recently completed, 10-year study in America involving 14,000 male physicians who were 50 or older, found that regularly taking multivitamins and minerals every day reduced the number of subject in the study who developed cancer by about 8 percent. The highest benefits were for those who had cancer earlier in their lives. However taking the vitamin supplements not reduce the rate of prostate cancer. The researchers found no evidence of side effects apart from occasional skin rashes.
Previous similar studies on the effects on cancer have been inconclusive - some positive and some negative. The results for the new study are promising but the researchers warned that the study did not show cause and effect and there may be linkages with lifestyle and other factors. Certain vitamins are antioxidants and may help protect aging cells from damage caused by free radicals. The other issue is that doctors may be atypical of the rest of the population. Generally people who take vitamins are a relatively healthy to begin with. These people tend to eat healthy diets, monitor their weight and are physically active. In these circumstances it is separate the benefits of taking vitamins with general good lifestyle of the subjects.
Conclusion: There is no clear evidence of the benefits of taking daily vitamin and nutrient supplements, but they probably do no harm unless the doses are too high. Vitamin overdose is a genuine problem.
|
Child
|
Child
|
Male
|
Male
|
Male
|
Female
|
Female
|
Female
|
|
|---|---|---|---|---|---|---|---|---|
|
NUTRIENT
|
4-8
|
9-13
|
14-18
|
19-50
|
>50
|
14-18
|
19-50
|
>50
|
|
Vitamins (Per Day)
|
||||||||
|
vitamin A - retinol
|
400 mcg
|
600 mcg
|
900 mcg
|
900 mcg
|
900 mcg
|
700 mcg
|
700 mcg
|
700 mcg
|
|
vitamin C - ascorbic acid
|
25 mg
|
45 mg
|
75 mg
|
90 mg
|
90 mg
|
65 mg
|
75 mg
|
75 mg
|
|
vitamin D
|
5 mcg
|
5 mcg
|
5 mcg
|
5 mcg
|
10 mcg
|
5 mcg
|
5 mcg
|
10 mcg
|
|
vitamin E
|
7 mg
|
11 mg
|
15 mg
|
15 mg
|
15 mg
|
15 mg
|
15 mg
|
15 mg
|
|
vitamin K
|
55 mcg
|
60 mcg
|
75 mcg
|
120 mcg
|
120 mcg
|
75 mcg
|
90 mcg
|
90 mcg
|
|
vitamin B1 - thiamin
|
0.6 mg
|
0.9 mg
|
1.2 mg
|
1.2 mg
|
1.2 mg
|
1.0 mg
|
1.1 mg
|
1.1 mg
|
|
vitamin B2 - riboflavin
|
0.6 mg
|
0.9 mg
|
1.3 mg
|
1.3 mg
|
1.3 mg
|
1.0 mg
|
1.1 mg
|
1.1 mg
|
|
vitamin B3 - niacin
|
8 mg
|
12 mg
|
16 mg
|
16 mg
|
16 mg
|
14 mg
|
14 mg
|
14 mg
|
|
vitamin B5 - pantothenic acid
|
3 mg
|
4 mg
|
5 mg
|
5 mg
|
5 mg
|
5 mg
|
5 mg
|
5 mg
|
|
vitamin B6 - pyridoxine
|
0.6 mg
|
1.0 mg
|
1.3 mg
|
1.3 mg
|
1.7 mg
|
1.2 mg
|
1.3 mg
|
1.5 mg
|
|
vitaminB12
|
1.2 mcg
|
1.8 mcg
|
2.4 mcg
|
2.4 mcg
|
2.4 mcg
|
2.4 mcg
|
2.4 mcg
|
2.4 mcg
|
|
biotin
|
12 mcg
|
20 mcg
|
25 mcg
|
30 mcg
|
30 mcg
|
25 mcg
|
30 mcg
|
30 mcg
|
|
choline
|
250 mg
|
375 mg
|
550 mg
|
550 mg
|
550 mg
|
400 mg
|
425 mg
|
425 mg
|
|
folate - folic acid
|
200 mcg
|
300 mcg
|
400 mcg
|
400 mcg
|
400 mcg
|
400 mcg
|
400 mcg
|
400 mcg
|
|
Minerals (Per Day)
|
Child
|
Child
|
Male
|
Male
|
Male
|
Female
|
Female
|
Female
|
|
calcium
|
800 mg
|
1300 mg
|
1300 mg
|
1000 mg
|
1200 mg
|
1300 mg
|
1000 mg
|
1200 mg
|
|
chromium
|
15 mcg
|
21 mcg
|
35 mcg
|
35 mcg
|
30 mcg
|
24 mcg
|
25 mcg
|
20 mcg
|
|
copper
|
440 mcg
|
700 mcg
|
890 mcg
|
900 mcg
|
900 mcg
|
890 mcg
|
900 mcg
|
900 mcg
|
|
fluoride
|
1 mg
|
2 mg
|
3 mg
|
4 mg
|
4 mg
|
3 mg
|
3 mg
|
3 mg
|
|
iodine
|
90 mcg
|
120 mcg
|
150 mcg
|
150 mcg
|
150 mcg
|
150 mcg
|
150 mcg
|
150 mcg
|
|
iron
|
10 mg
|
8 mg
|
11 mg
|
8 mg
|
8 mg
|
15 mg
|
18 mg
|
8 mg
|
|
magnesium
|
130 mg
|
240 mg
|
410 mg
|
410 mg
|
420 mg
|
360 mg
|
315 mg
|
320 mg
|
|
manganese
|
1.5 mg
|
1.6 mg
|
2.2 mg
|
2.3 mg
|
2.3 mg
|
1.6 mg
|
1.8 mg
|
1.8 mg
|
|
molybdenum
|
22 mcg
|
34 mcg
|
43 mcg
|
45 mcg
|
45 mcg
|
43 mcg
|
45 mcg
|
45 mcg
|
|
phosphorus
|
500 mg
|
1250 mg
|
1250 mg
|
700 mg
|
700 mg
|
1250 mg
|
700 mg
|
700 mg
|
|
selenium
|
30 mcg
|
40 mcg
|
55 mcg
|
55 mcg
|
55 mcg
|
55 mcg
|
55 mcg
|
55 mcg
|
|
zinc
|
5 mg
|
8 mg
|
11 mg
|
11 mg
|
11 mg
|
9 mg
|
8 mg
|
8 mg
|
|
potassium
|
3.8 g
|
4.5 g
|
4.7 g
|
4.7 g
|
4.7 g
|
4.7 g
|
4.7 g
|
4.7 g
|
|
sodium
|
1.2 g
|
1.5 g
|
1.5 g
|
1.5 g
|
1.3 g
|
1.5 g
|
1.5 g
|
1.3 g
|
|
chloride
|
1.9 g
|
2.3 g
|
2.3 g
|
2.3 g
|
2.0 g
|
2.3 g
|
2.3 g
|
2.0 g
|