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2013

December
Liver Toxicity with Supplements, Including Green Tea -- An increase in cases of liver toxicity associated with dietary supplement use has recently been reported. In an article about the findings, The New York Times reports that bodybuilding supplements and products containing green tea extracts are among those associated with such cases. For more information about green tea extracts and toxicity, see the Concerns and Cautions section of the Green Tea Supplements Review >> 
More Evidence of What Multivitamins Don't Do -- Several new studies about multivitamins were published this week. The bottom line: In well-nourished people, multivitamins don't reduce the risk of cardiovascular disease or overall-mortality, nor improve cognition and memory. Although some studies have suggested a modest benefit in reducing the risk of certain cancers, no clear cancer benefit for multivitamins has been established. For more information, see the updates to the Multivitamins and Multimineral Supplements Review >>  
Probiotic Significantly Reduces Antibiotic-Associated Diarrhea -- A new study using a combination of probiotic organisms reduced the incidence of diarrhea by half among hospitalized individuals receiving antibiotics. Two doses were tried, and the higher dose was more effective. For details about this probiotic and how it was taken, along with additional information and our tests of probiotics, see the updated Probiotic Supplements Review >>    
B-12 Deficiency and Acid Inhibitors -- A large, new study found the risk of vitamin B-12 deficiency to be significantly higher among people taking proton pump inhibitors (e.g., Prevacid, Prilosec) or H2-blockers (e.g., Pepcid, Zantac) than among those not taking these medications. The drugs reduce acid production in the stomach, but acid is needed to release B-12 from foods, so deficiency can occur. B-12 supplements can help because acid is not needed for their absorption. For details -- and our reviews of supplements with vitamin B-12 -- see the updated B Vitamin Supplements Review >>   

Other supplements which should or should not be used with these medications are discussed in the Proton Pump Inhibitors article, which is part of the extensive Drug Interactions section of our website (where you can look up interactions for other drugs you may be taking.) 


November
Lower Vitamin D in Blacks May Be Sufficient -- The traditional method of assessing vitamin D levels may not be appropriate for most black people, according to a new study. Due to a genetic variant, this approach classifies many black individuals as "deficient" in vitamin D although their levels may be adequate. For details see the update to the  Vitamin D Supplements Review >> 
Probiotics for Oral Health? -- For people with periodontitis (inflammation around the teeth), a new study showed a probiotic lozenge resulted in additional improvement over standard dental scaling and chlorhexidine rinse. Get the details, as well as our tests of probiotics, in the updated Probiotic Supplements Review>>
Latest Supplement Recommendations -- New draft recommendations on vitamin and mineral supplement use were published this week by the U.S. Preventive Services Task Force. The recommendations apply only to healthy adults without nutritional deficiencies. They focus only on the use of supplements for the prevention of cardiovascular disease and cancer at doses not exceeding tolerable upper intake levels. The recommendations are based on existing science and are generally consistent with information already presented in ConsumerLab.com's Product Reviews.  We have summarized the recommendations below, with links to more information in ConsumerLab.com's reports:

- Beta-Carotene and Vitamin E:  Supplementation with either does not provide a benefit. Vitamin E does not pose a risk of harm, but beta-carotene increases the risk of lung cancer in people at risk for lung cancer.

- Other Single Vitamins, Minerals, Pairs, and Multivitamins: There is inadequate evidence regarding a benefit or a risk of harm.

The task force stressed that at excessive doses (above tolerable upper intake levels) there is evidence of harm with supplementation, such as with vitamin A and vitamin D
Amino Acids Speed Recovery From Knee Surgery -- A study of men and women receiving knee replacement surgery showed that taking essential amino acids (including branched-chain amino acids) twice daily before and after surgery reduced muscle loss and speeded recovery. For details, including dosage, plus our reviews of amino acid supplements, see the updated Muscle Enhancers Review >> 
Caution with Calcium for Women with High Cholesterol -- A study in which women with high cholesterol  were given a daily calcium supplement showed a negative effect in those who were post-menopausal.  Get the details, including the calcium dosage used, in the updated Calcium Supplements Review>>
Too Much Fish Oil May Cause Adverse Effects -- Recent animal studies using EPA and DHA from fish oil suggest that very high intakes may dampen immunity. Might you be getting too much? Find out in the update to the Fish Oil and Omega-3 Fatty Acid Supplements Review>>

October
FDA Finds Another Generic Drug Not Equivalent -- According to the FDA, a marketed generic version of the antidepressant buproprion hydrochloride XL (300 mg) is not equivalent to the brand name Wellbutrin XL and the product is being removed from the market. One year ago, another generic version of this drug was removed from the market for the same reason. ConsumerLab.com first reported potential problems with these products in 2007 but the FDA was slow to take action. For details, see the updated in the Wellbutrin vs Generic Budeprion Review >>
Multivitamins May Improve Breast Cancer Survival -- A study of women with invasive breast cancer found that those who took multivitamins were 30% less likely to die of the disease during the study than women who did not take multivitamins, suggesting a possible role for supplementation. For more information about the study, as well as tests of popular multivitamins, see the updated Multivitamin and Multimineral Supplements Review >> 
Probiotic Helps Prevent Recurrence of Diverticular Disease -- A new study found a major reduction in the recurrence of symptomatic diverticular disease when people were given a specific probiotic. Further reduction occurred with a combination of the probiotic and a prescription medication. For details about the treatment, including dosage, and our tests of probiotic supplements, see the updated  Probiotic Supplements Review >>     
Most Herbal Products Don't Contain Listed Herb -- DNA analysis of 44 herbal products from Canada and the U.S. found that only 48% contained the herb listed on the label and one-third of these products contained contaminants or fillers not listed on the label (Newmaster, BMC Med 2013). Nine percent of products contained only rice or wheat and none of the listed herb. Many cases of herb substitution were reported, including senna (a laxative) in a product labeled as St. John's wort. Several products were contaminated with feverfew , which should not be consumed by pregnant women and may react with a variety of medications. The researchers, from the University of Guelph in Ontario, did not disclose the identities of the tested products, which were single-ingredient herbs sold as capsules, powders, or tablets. Significant challenges continue to exist for routine use of DNA analysis of herbs, but ConsumerLab.com may use this technique where appropriate in the future, alongside other analytical techniques in its Product Reviews.   
Vitamin D for Post-Menopausal Women -- A study compared the effects of low-dose and high-dose vitamin D on bone mineral density in post-menopausal women who were also supplemented with calcium. Both dosages helped prevent loss of bone mineral density, but the higher dose was less efficient in reducing bone turnover, i.e., bone loss, contrary to what the researchers expected.  For details, including dosage, see the updated Vitamin D Supplements Review>>
Vitamin D for Adolescents -- A study found that vitamin D supplementation increased bone density in the hips of adolescent girls, but not of boys. Interestingly, a high dose appeared to have less effect than a low dose. For details, including dosage and our tests of vitamin D supplements, see the updated Vitamin D Supplements Review>>

September
When Vitamin D Doesn't Help -- A recent study in postmenopausal women in New York showed that taking a vitamin D supplement did not reduce bone loss (based on measurements of markers of bone turnover). However, calcium supplementation did appear to help. Why? It all has to do with how much vitamin D and calcium the women were already getting without the supplements. You can find out the amounts and get more details in the update to the Vitamin D Supplements Review >>
Green Tea to Treat Fibroids -- A new study suggests that green tea extract may help shrink uterine fibroids (common in women of childbearing age) and reduce symptoms. For details, as well as test results and comparisons of green tea extracts and brewable teas and drinks, see the updated Green Tea Review >>
Fish Oil and Arthritis -- A study of several thousand women found those who consumed at least a moderate of amount omega-3 fatty acids (EPA and DHA) from fish in their diets had just half the risk of developing rheumatoid arthritis over the course of the study than did women with lower intakes.  For details about the amount of omega-3's and fish consumption associated with preventing arthritis, other uses of omega-3's, and tests of fish/marine oil supplements, see the Fish/Marine Oil Supplements Review>>
B Vitamin Supplements for Stroke? -- A review of 14 clinical studies suggests that B vitamins may help prevent stroke. However, a deep reading of the report shows the benefit to be slight, at best.  For details about the study, other uses of B vitamins (including B6, B-12, folic acid, niacin and complexes), and tests of these supplements, see the B Vitamin Supplements Review>>  
Chromium Concern -- A new study shows that chromium supplementation can sometimes cause a worsening of insulin sensitivity, raising some concern about its use. For details (as well as test results and comparisons for 8 chromium supplements) see the updated Chromium Supplements Review >>
Calcium During Breast Cancer Treatment -- A recent analysis of clinical studies concluded that supplementation with calcium and vitamin D during breast cancer treatment does not help maintain bone mineral density, although often given for this purpose. Calcium and vitamin D may certainly play other important roles. For more details, as well as test results and comparisons for 33 calcium supplements, see the updated Calcium Supplements Review >>

August
Antioxidants: Too Much of a Good Thing? --
A new, long-term study of Americans found the risk of dying over the course of the study (about 14 years) was lowest when antioxidant levels in the blood were above the lowest levels (the bottom 20% of the population). However, for people in the top 20% of blood levels for vitamins A and E, the risk of death increased compared to people with moderate levels. For selenium and beta-carotene, there was no significant difference in the death rate between moderate and high levels, although for vitamin C some additional benefit was seen at high, but not the highest, levels.
 
The results suggest that antioxidant supplements may be useful for those who are nutritionally deficient, but, as noted by the researchers, "beyond a certain threshold, higher levels do not lead to additional benefit, and may potentially be toxic." More details (including specific serum levels) are found in the linked updates to the following reviews, which include our test results and quality ratings of products:
 
 
  
  
Vitamin D for Hypertension? -- Some studies have suggested a modest reduction in high blood pressure with vitamin D supplementation. However, a recent study did not find such a benefit - although a closer look reveals why these results may not tell the full story. Get the details, plus more information about vitamin D and cardiovascular health, and test results for 55 vitamin D supplements, in the updated Vitamin D Supplements Review >>
Ginseng Reduces Cancer-Related Fatigue -- A well-controlled clinical trial recently showed reduced fatigue among cancer patients given a particular type and dose of ginseng. Get the details, as well as our test results for 16 ginseng supplements, in the updated Ginseng Supplements Review >> 
New Probiotic Study -- A new study raises questions about the efficacy of taking probiotics to reduce the occurrence of antibiotic-associated diarrhea. For more details, as well as test results and comparisons for 29 probiotic supplements, see the updated Probiotic Supplements Review >>   
Supplement Helps Dry Eye -- A supplement containing omega-6 (from black currant seed oil) and omega-3 fatty acids (from fish oil) was recently shown to improve symptoms of dry eye. Get the details about this formula (plus our test results of other omega-3 and -6 fatty acids supplements) in the updated Black Currant, Borage, Evening Primrose, and Flaxseed Oils Review >>
5-HTP Concern -- Three cases of eosinophilia-myalgia syndrome (EMS) have been reported among people taking 5-HTP, a compound related to L-tryptophan. EMS is a debilitating immune condition which has occurred in people taking L-tryptophan, but there were no previous reports of it being caused by 5-HTP. Get the details in the the updated review article on L-Tryptophan and 5-HTP >>

July
Resveratrol May Blunt Positive Effects of Exercise -- Although experiments in animals suggest that resveratrol improves athletic endurance, a new, placebo-controlled study in men found it to blunt some of the positive effects of exercise. Get the details plus test results for 20 resveratrol supplements and more information about resveratrol's effects in the updated Resveratrol Supplements Review >>  
Vitamin D May Protect Bones From Aging -- Researchers recently analyzed bone samples from people who were deficient in vitamin D and found changes indicating that the bone had "aged" and was more brittle than bone from people not deficient in vitamin D. For details about this study -- including the levels of vitamin D associated with Vitamin D May Protect Bones from Aging -- Researchers recently analyzed bone samples from people who were deficient in vitamin D and found changes indicating that the bone had "aged" and was more brittle than bone from people not deficient in vitamin D. For details about this study -- including the levels of vitamin D associated with these changes, studies of other effects of vitamin D, as well as test results and comparisons for 55 vitamin D supplements, see the updated Vitamin D Supplements Review >>   
Soy Protein to Prevent Prostate Cancer? -- Prostate cancer occurs less frequently in parts of the world where people eat more soy. So researchers recently gave a soy protein drink, or a placebo drink, to men who previously had prostate cancer to see if it reduced the risk of the cancer recurring. Learn what they found in the updated Protein Powders and Drinks Review >>
Fish Oil Linked to Prostate Cancer? -- Headlines this week about a study showing an association between the fatty acids in fish oil and the development of prostate cancer have stirred concerns about consuming fish and fish oil supplements. For details about this study and studies of other effects of fish oil and omega-3 fatty acids, as well as test results and comparisons for 74 fish and other marine oil supplements, see the updated Fish/Marine Oil (Omega-3) Supplements Review >>
Calcium and Vitamin D to Prevent Fractures -- A large study among post-menopausal women receiving hormone therapy showed a much lower rate of hip fracture among those who received a specific calcium/vitamin D supplement compared to those who did not get the supplement. For details about the supplement, as well as test results and comparisons for 13 calcium/vitamin D supplements, see the updated Calcium Supplements Review >>
Fish Oil for Brain Function -- Healthy people, ages 50 to 75, given a specific fish oil supplement for 6 months experienced significant gains in their performance on visual tasks, reading, and verbal fluency in a recent placebo-controlled study. Brain scans also showed significant gains in the structure and volume of tissue in several areas of the brain. For details about the type and dose of fish oil taken, as well as test results and comparisons for 74 fish and other marine oil supplements, see the updated Fish/Marine Oil (Omega-3) Supplements Review >>









 

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