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ConsumerLab.com Answers
Question: Which supplements are important after bariatric surgery (i.e., weight loss or stomach-reducing surgery)? Are there any I should avoid?
Answer: Weight loss surgeries such as gastric bypass, gastric sleeve, and gastric band procedures, reduce the amount of food and liquid a person comfortably digest in one sitting, leading to smaller meals and potentially, inadequate nutrient intake. Gastric bypass (re-routing around the stomach) and gastric sleeve surgery (removing a portion of the stomach) also reduce stomach acid and normal digestive action, leading to reduced absorption of various vitamins and minerals. The use of supplemental vitamins and minerals is recommended for gastric bypass and gastric sleeve patients, and sometimes for gastric band patients. However, for bypass and sleeve patients, the changes in digestion and nutrient absorption also mean that some supplements may not be tolerated or absorbed as well as others. For details about supplements to take or avoid, see the full answer >>
ConsumerLab.com Answers
Question: Are supplements with amino acid chelated minerals better than those with other forms of minerals?
Answer:
Minerals, like magnesium and iron, are metal ions which like to attach to other compounds. The compounds to which they attach can affect how well they are absorbed and how available they are for use in the body. An amino acid chelated mineral is one in which a mineral has been chemically attached to an amino acid, and there is evidence that some, but not necessarily all, of these types of compounds may improve mineral absorption. For information about specific chelated amino acids, such as iron bis-glycine, magnesium diglycinate, zinc bis-glycinate, and selenomethionine (a chelate of selenium), see the full answer >>
Question: Are enteric coated supplements better than non-enteric coated ones?
Answer: Enteric coatings help protect supplement ingredients from being released in the stomach and keep them away from stomach acid and enzymes. This allows the supplement to stay intact until it reaches the less acidic small intestine (where most nutrient absorption takes place). An enteric coating may also be desirable for ingredients which, for some people, otherwise cause an unpleasant aftertaste. Consequently, with ingredients that need protection it is sometimes worthwhile to purchase an enterically coated supplement. However, enteric coatings are not always necessary or beneficial, and, in some case, may just be an expensive gimmick. There are also some concerns about enteric coatings of which you should be aware. See the full answer (with information about enteric coatings for fish oil, marine oils, probiotics, garlic, and SAMe)>>
ConsumerLab.com Answers
Question: Do any supplements help relieve stress?
Answer: Fish oil may blunt some of the effects of mental stress, such as increased heart rate and nervous activity. Several clinical studies show ashwagandha may help to relieve symptoms in people with anxiety. And, interestingly, a particular probiotic has been shown to lower levels of the "stress" hormone cortisol, and measures of psychological distress such as depression and anger.
L-theanine, an amino acid found in black and green tea, has been shown to reduce stress responses without causing drowsiness, and there is some evidence that the herbs passionflower and lemon balm may be helpful for anxiety.
One clinical trial found 500 mg of holy basil leaf extract taken twice daily significantly reduced measures of anxiety in men and women (Bhattacharyya, Nepal Med Coll J 2008). See the Encyclopedia article about Ayurvedic medicine for other uses for this herb - which is listed by its scientific name, Ocimum sanctum.
Ginseng is sometimes promoted for reducing stress, although one clinical study found it did not have an effect on cortisol levels. There is weak evidence that valerian supplements may produce a calming effect in stressful situations.
Be aware that low blood levels of iron and vitamin B6 have been associated with stress responses such as hyperventilation and panic attacks in women (Mikawa, Acta Med Okayama 2013), so be sure you're getting sufficient intake of these nutrients. There is some evidence that daily supplementation with a multivitamin-multimineral supplement may help people to cope with stressful situations.
For more information, use the links above, and see the Encyclopedia article about Stress.
ConsumerLab.com Answers
Question: Can prenatal vitamins have too much folic acid? Mine has 800 mcg, but isn't that more than what's recommended? Is this dangerous to me or my baby?
Answer: Prenatal vitamins can have too much folic acid, many do, and there is potential risk associated with this.
Folic acid is a synthetic form of the B vitamin folate(B9) which naturally occurs in foods, such as green leafy vegetables. Folate can help reduce the risk of your baby being born with spina bifida (a leading cause of childhood paralysis) and other birth defects. While most adults need 400 mcg of folate daily, pregnant women need 600 mcg. To be sure you get this, it's suggested that you take a supplement with 400 mcg of folic acid and that you get the rest of your folate from your diet — from foods such as dark green leafy vegetables, oranges, and grain products enriched with folic acid.
Unfortunately, many prenatal supplements provide 800 mcg or more of folic acid — double the recommended amount from a supplement. That's not all. Folic acid is absorbed much better (about 70% better) than folate from foods. This means that a prenatal supplement with 800 mcg of folic acid gives you the equivalent of 1,360 mcg of folate. (Labels will start making this clear 2018, but current labels don't). On top of this, many manufacturers put in extra folic acid (30% or more is not uncommon), so it's quite possible that your supplement which lists 800 mcg of folate from folic acid is giving you the equivalent of about 1,800 mcg of folate. Add to that the 300 to 400 mcg of folate you're likely already getting from foods and you can see that this can easily total of over 2,000 mcg of folate per day!
The upper tolerable intake level (UL) for folate is 1,000 mcg (which applies only to that consumed from supplements and fortified foods from synthetic forms like folic acid) — so any supplement with more than 586 mcg of folic acid will cause you to exceed the limit. It's best not to exceed this because prolonged intake of excessive folic acid can cause kidney damage and can complicate the diagnosis of vitamin B-12 deficiency (folic acid supplementation can mask a symptom of vitamin B-12 deficiency). Of particular concern to pregnant women is that excessively high blood levels of folate (>59 nmol/L) in their blood was found to be associated with an approximate twofold increased risk of autism in their children according to an observational study in Baltimore in which 10% of women exceeded this level (Raghavan, International Meeting for Autism Research 2016). The study also found that when blood levels of both folate and vitamin B-12 were excessively high, the risk of autism was 17.6 times greater. (Note: Getting adequate folate during pregnancy may reduce the risk of autism; the concern is with getting too much).
So what should you do?
ConsumerLab.com has tested and compared many prenatal supplements and other multivitamins. Unfortunately, most on the market tested by CL to-date have too much folic acid (more will be tested in mid-2017). For now it may be safest to skip a "prenatal" vitamin with 800 mcg of folic acid and, instead, choose a daily multivitamin which provides 400 mcg of folic acid. The multi should also provide other nutrients of particular importance during pregnancy such as iodine (150 mcg), vitamin D (600 IU), and calcium (1,000 mg per day is the daily requirement, but don't take more than 500 mg at a time from a supplement). A challenge, however, is getting adequate iron, since the daily requirement during pregnancy (27 mg) is higher than for other pre-menopausal women (18 mg). A women's multi can provide all the nutrients listed above, but typically just 18 mg of iron, so you'll need to get extra iron from your diet. Alternatively, you can choose another multi and take a separate iron supplement providing about 27 mg of iron.
Your Prenatal Vitamin Needs a Check-up with CL founder, Dr. Tod Cooperman
ConsumerLab.com Answers
Question: Are the "% DV" numbers on vitamin supplement labels really based on what I need?
Answer: Yes and no. The most current DVs (Daily Values), updated by the FDA in 2016, do accurately reflect the basic daily intake requirements for vitamins and minerals. However, companies are not required to use the updated DVs on product labels until at least 2020. In the meantime, many vitamin and supplement labels will be misleading — providing "%DV" values based on terribly out-dated DVs establish in the 1960s. The new DVs include separate values for infants, very young children, and women who are pregnant and lactating.
Some important changes in 2016 to the DVs for most adults and children over age 4 include the following. (Keep in mind that your supplement label is most likely still based on old DVs):
Vitamin D: The DV doubled, from 400 IU (10 mcg) to 800 IU (20 mcg). (Note: Many people who are not deficient in vitamin D may already be taking too much.) Labels will also have to list vitamin D in different units (mcg), but can include the familiar IU (international units) values (1 mcg = 40 IU).
Folate: Recognizing that about 70% more folate is absorbed from supplements containing folic acid (synthetic folate) than from foods naturally containing folate, the DV (which remains at 400 mcg) is now based on "dietary folate equivalents," shown as "DFE". A supplement with 400 mcg of folic acid is to be labeled as providing 170% DV rather than 100% DV.
Vitamin B-12: The DV decreased from 6 mcg to 2.5 mcg
ConsumerLab.com lists the new DVs (as well as RDAs and Upper Tolerable Intake Levels (ULs)) for each vitamin and mineral at www.consumerlab.com/rdas.
You'll find further information about each nutrient within our Product Reviews, including our tests, reviews, ratings, and comparisons of products.
ConsumerLab.com Answers
Question: Which supplements can help treat constipation?
Answer: A number of supplements may be helpful in treating or preventing constipation. Fiber supplements, such as psyllium and glucomannan (a water-soluble fiber) may help to relieve constipation (Note: there is a safety concernwhen using glucomannan). Ground flaxseed, another source of fiber, may also be helpful. (See ConsumerLab.com's Fiber Supplements Webinar for more information about these supplements for constipation as well as for other uses.)
A specific probiotic product was found to significantly increase the number of bowel movements per week in people with chronic constipation. (Other strains have been found to be helpful for constipation associated with IBS).
Magnesium and aloe vera juice (with latex) can help to relieve constipation due to their laxative effects (Note: There are safety concerns with aloe latex -- see the "Concerns and Cautions" section of the Aloe Vera Review before using).
See the Encyclopedia article about Constipation for information about other proposed treatments.
Be aware that constipation may be a side-effect of certain supplements, especially iron, and to a lesser degree, calcium (see the "ConsumerTips" sections of the respective ConsumerLab.com Reviews for more about forms of these minerals which may be less likely to have this effect). Other supplements reported to cause constipation, although less frequently, include nattokinase, chlorella, NAC (N-acetyl cysteine) and beta-sitosterol.
Excessive intake of vitamin D as a supplement can cause hypercalcemia (too much calcium in the blood) with symptoms including constipation.
ConsumerLab.com Answers
Question: Which supplements help to improve energy and decrease fatigue?
Answer: Getting adequate sleep, eating a healthy, well-balanced diet, and regular exercise are the best ways to maintain your energy. However, we all have times when we could benefit from an energy boost. (If you are frequently tired, be sure to consult your physician about potential causes, as discussed below).
Certain supplements may help increase energy and decrease fatigue.
CoQ10, which plays a role in energy production in cells, has been shown to decrease fatigue in people with conditions such as heart failure and Gulf War Illness. One small study suggested it may increase self-assessed "vitality" in older adults. (Be aware that taking CoQ10 in the evening can cause insomnia in some people).
Curcumin (from turmeric) has been shown to reduce fatigue in older men and women using a particular branded formula.
Ashwagandha may reduce fatigue in middle-aged adults with moderate to severe anxiety.
Cocoa flavanols may help reduce self-reported mental fatigue in healthy adults, according to one study.
Ginseng is a popular ingredient in supplements promoted for increasing energy and vitality. Although there is little evidence to support this effect in healthy people, there is some evidence it may increase energy in people with cancer-related fatigue.
Carnitine may help reduce fatigue in older men with symptoms of sexual dysfunction, depression and fatigue.
B vitaminsare involved in the metabolism of food to release energy, and deficiency in vitamin B-12 is known to cause fatigue. However, if you already get an adequate amount of the B vitamins in your diet and are not deficient in them, supplementing with additional amounts of B vitamins is not known to improve performance. Be aware that energy drinks often contain much higher doses of B vitamins than needed — sometimes amounts above tolerable limits. Energy drinks also commonly contain significant amounts of caffeine or ingredients which naturally contain caffeine such as guarana and cola nut. Although caffeine does not actually provide energy, it acts as a stimulant and can reduce fatigue. Be aware that energy drinks can increase blood pressure, and stroke and liver injury have been reported in people consuming certain energy drinks.
Energy bars, or nutrition bars, can be a good source of real energy (calories), especially if you are on the go and haven't had a chance to eat a real meal, and also provide vitamins and minerals. It's important to choose carefully as some are high in sugar, or contain sugar substitutes that may upset your stomach. Some also contain caffeine.
Supplements that provide iodine, such as kelp supplements and potassium iodide, are often promoted to increase energy. However, there is little evidence for this effect unless they are being used to treat hypothyroidism due to iodine deficiency.
Rhodiola rosea and maca supplements are sometimes promoted to increase energy or reduce fatigue, however, there is not enough evidence to support these supplements for this use.
Iron deficiency can cause fatigue. Consequently, correcting iron deficiency with iron supplementation can reduce related fatigue. Interestingly, iron supplementation has even been shown to reduce fatigue in women who are not anemic but have ferritin levels in the lower end of normal range.
Question: Do any supplements help for restless legs syndrome?
Answer: Although no large studies have been conducted, smaller studies suggest a possible role of supplements in reducing the symptoms of restless legs syndrome (RLS), a condition that causes uncomfortable "creepy-crawly" sensations, agitation, and the need to move the legs when trying to fall asleep. Women are twice as likely to suffer from restless legs syndrome than men, and it occurs more often with increasing age (Wang, Sleep Med 2009).
People with deficient or low blood levels of iron are also more likely to experience RLS. As discussed in more detail in the "What It Does" section of the Iron Supplements Review, a study found that taking a combination of high-dose iron and vitamin C (which helps to increase iron absorption) can decrease symptom severity in people whose blood levels of iron are low. However, it's important to consult your physician before supplementing with iron for RLS.
As discussed in the "What It Does" section of the Magnesium Supplements Review, a preliminary study suggested that taking magnesium in the evening could be helpful for RLS; however, there have not been large, well-controlled studies investigating this treatment.
Similarly, as discussed in the "What It Does" section of the Potassium Supplements Review, one preliminary study suggested that potassium may help reduce the severity of RLS symptoms, but no well-controlled studies have been conducted to prove this.
As discussed in our Encyclopedia article about Restless Legs Syndrome, there is very preliminary evidence that folate and vitamin E might be helpful.
Be aware that melatonin supplements may increase leg movements in people with restless legs syndrome RLS. Caffeine, alcohol, SSRI antidepressants, antihistamines, and most antipsychotic and antinausea medications can potentially increase RLS symptoms (Cotter, Ther Clin Risk Manag 2006).
Question: Do any supplements help reduce the symptoms of premenstrual syndrome (PMS)?
Answer: There is fairly good evidence that calcium supplements can significantly reduce the major symptoms of PMS, such as mood swings, pain, bloating, irritability, depression, back pain, and food cravings. There is also some evidence that magnesium, vitamin E, Gingko biloba, royal jelly, and chasteberry, may be helpful for reducing symptoms of PMS.
The evidence is mixed on whether or not other supplements which are commonly promoted for PMS, such as vitamin B6 and evening primrose oil, are helpful.
More about the evidence for these supplements, dosage, and information about other proposed treatments, is found in the Encyclopedia article about Premenstrual Syndrome.
In addition, be aware that women with a high intake of iron from certain sources have been shown to have a lower risk of suffering PMS than those with lower intakes -- while high intakes of potassium have been associated with an increased risk of PMS.
Question: Why is iron not in many multivitamins? How can I find one that does contain iron?
Answer: Iron from a supplement, like a multivitamin, is important for those who are most likely to be deficient in iron: women who have not gone through menopause (particularly pregnant women) and children. Men are least likely to be iron deficient. In fact, the CDC has estimated that 29% of men are at-risk for iron excess.
Consequently, multivitamins for men and older women typically contain little or no iron, while those for younger women and children tend to contain iron. Some general multivitamins contain iron while others don't.
Disturbingly, in its product review of multivitamins in 2017, ConsumerLab found that half of the multivitamins for children and 20% of those for women (excluding those for post-menopausal women) did not include iron.
Don't expect iron in gummy vitamins.
Likely due to the unpleasant taste of iron, manufacturers appear to be leaving iron out of gummy vitamins. (Another possible reason for excluding iron from gummies for children is to avoid the possiblity of an iron overdose in the event that a child consumes too many gummies due to their candy-like appearance.) Gummy multivitamins also happened to be much more likely to fail ConsumerLab's tests of quality than tablets, as they often contained much less or much more of the listed amounts of ingredients. (Note: Several large tablets also failed testing due to slow disintegration times.)
In short, for children and young women, a multivitamin with iron may be helpful to avoid iron deficiency — but be aware that you probably won't get it from a gummy. For men and older women who are not vegetarian, it's usually best to avoid a supplement with iron.
You can check amounts of iron in multivitamins tested by ConsumerLab.com by checking the Mineral Ingredients page in the review, which lists the amount of each mineral in each product reviewed. The review will also show you which products passed or failed testing and which are ConsumerLab's Top Picks based on quality and cost.
Also, see the Iron section of the Multivitamin Review to find out how much iron you need, based on your age, gender and specific needs, and how you can get it from foods.
If you specifically need an iron supplement, check ConsumerLab.com's Iron Supplements Review.
ConsumerLab.com Answers
Question: Is it true that calcium interferes with iron absorption? Is it a problem to take a multivitamin containing both minerals?
Answer: Taking calcium can inhibit iron absorption by as much as 62%, but this depends on the dose of calcium. This interaction is of greatest concern for younger women, as they are the most likely to suffer iron deficiency. For more details about this interaction and how to avoid or minimize it, and about other minerals and foods that can inhibit iron absorption, see the "What to avoid when taking" section of the Iron Supplements Review >>
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Product Reviews
Iron Supplements Review
Initial Posting: 12/28/17 Last Update: 10/16/18
Find the Best Iron Supplement
See Which Iron Supplements Passed CL's Tests and the Top Picks
Alphabetical list of iron supplement brands in report
Country Life Easy Iron
Life Extension Iron Protein Plus
Solaray BioCitrate Iron
Feosol Bifera HIP & PIC Iron
Member's Mark [Sam's Club] Iron
Solgar Gentle Iron
Fergon
Nature Made Iron
Spring Valley (Walmart) Iron
Ferro-Sequels
Nature's Bounty Gentle Iron
VegLife Vegan Iron Chewable
Floradix Iron Tablets
NovaFerrum Pediatric Drops Liquid Iron
Vitamin Friends Iron
Garden of Life mykind Organic Plant Iron & Organic Herbs
NOW Iron
Well at Walgreens Slow Release Iron
GNC Gentlesorb Iron
Rexall [Dollar General] Iron
Wellesse® Liquid Iron
Jamieson Iron
Make sure the iron supplement you take passed our tests and is right for you! Isn't your health worth it?
Iron supplements can help to prevent and correct iron deficiency common in young women but also seen in children and among people taking drugs that reduce stomach acid. Iron supplementation may also reduce unexplained fatigue in women of child-bearing age, inhibit dry cough associated with ACE inhibitors, and reduce symptoms of restless legs syndrome in people with low ferritin levels.
But choosing an iron supplement can be difficult: There are many different forms and doses of iron available, a wide range of prices, and some may be better manufactured than others.
To help you choose the best iron supplement, ConsumerLab.com independently purchased, tested, and reviewed iron supplements. Our tests revealed that most iron supplements contained what they claimed. However, one iron supplement failed tests.
Among products that were Approved in testing, ConsumerLab.com then carefully selected those providing the best form and value as its Top Picks.
You must be a ConsumerLab.com member to get the full test results along with ConsumerLab.com's Top Picks and information on using iron. You'll get results for 22 supplements: 14 selected by ConsumerLab.com and eight that passed the same testing in CL's voluntary Quality Certification Program.
You'll get the following information about iron supplements in this comprehensive report:
Which iron supplements failed and which passed
Which iron supplements were Approved for their quality, offer the best value, and are CL's Top Picks
The pros and cons of different forms of iron (such as carbonyl iron, ferrous bisglycinate, ferrous fumarate, ferrous gluconate, and ferrous sulfate, as well as heme iron polypeptide, iron protein succinylate, polysaccharide iron complex, and plant-based iron) and which may be the best iron supplement for you
Iron dosage for specific applications, including anemia and unexplained fatigue
How to take iron to avoid stomach upset and increase absorption
Concerns, cautions, and potential drug interactions with iron supplements
ConsumerLab.com Answers -- for Iron Supplements Review
Question: Which supplements are important after bariatric surgery (i.e., weight loss or stomach-reducing surgery)? Are there any I should avoid? Get the answer >>
Question: Are supplements with amino acid chelated minerals better than those with other forms of minerals? Get the answer >>
Question: Are enteric coated supplements better than non-enteric coated ones? Get the answer >>
Question: Can prenatal vitamins have too much folic acid? Mine has 800 mcg, but isn't that more than what's recommended? Is this dangerous to me or my baby? Get the answer >>
Question: Are the "% DV" numbers on vitamin supplement labels really based on what I need? Get the answer >>
Question: Which supplements can help treat constipation? Get the answer >>
Question: Which supplements help to improve energy and decrease fatigue? Get the answer >>
Question: I've heard that soaking dried beans for 24 hours reduces the phytate level, allowing for greater access to nutrients. Is this true? Get the answer >>
Question: Do any supplements help for restless legs syndrome? Get the answer >>
Question: Do any supplements help reduce the symptoms of premenstrual syndrome (PMS)? Get the answer >>
Question: Why is iron not in many multivitamins? How can I find one that does contain iron? Get the answer >>
Question: Is it true that calcium interferes with iron absorption? Is it a problem to take a multivitamin containing both minerals? Get the answer >>
![Member's Mark [Sam's Club] Iron](https://cdn.consumerlab.com/images/products/6020_small_6020_small_MembersMark-Iron-Small-2017.jpg)
![Rexall [Dollar General] Iron](https://cdn.consumerlab.com/images/products/6025_small_6025_small_Rexall-Iron-Small-2017.jpg)
