Specific vitamins and a supplement (B vitamins, vitamin D, and calcium) may lower risk of stroke, blindness, and cancer
Wednesday, 25 February 2009
In recent blogs I have discussed studies showing that multivitamins may not to be helpful for preventing chronic diseases: Are multivitamins helpful or harmful when it comes to preventing chronic diseases? and Report Casts Doubt On Routine Vitamin Supplements. Also, in past blogs I’ve discussed why you should consider vitamin D supplementation: Vitamin D deficiency and diseases linked; Lack of vitamin D raises death risk; and Vitamin D may protect against heart attack, just to name a few.
However, there is evidence that specific vitamins may be helpful in some people. Today I want to tell you about two studies this week backing up my contention that a specific combination of B vitamins and calcium may be worthy of your consideration.
USA Today is reporting that High doses of B vitamins may help prevent stroke in high-risk people, new research suggests. Results showed that people who took the vitamins were 25% less likely to suffer a stroke over the study period than those who took placebo.
The finding comes from the Heart Outcomes Prevention Evaluation 2 trial of more than 5,500 men and women with heart disease. Participants were assigned to a daily regimen of either B vitamins or placebo pills for five years. The study involved 3,353 people who had suffered a stroke. The researchers added high- or low-dose B vitamins — folate, vitamin B12, and vitamin B6 — to state-of-the-art medical care for two years.
Previously reported findings from the trial were disappointing, suggesting that the B vitamins did not lower the risk of recurrent stroke. But this time, researchers looked at what happened when people actually took their medication.
In another exciting study about these three specific B vitamins, published Feb. 23 in the Archives of Internal Medicine, the USA Today reports that, “taking B vitamins could lower the risk for” age-related macular degeneration (AMD), the “leading cause of blindness in older Americans.”
For the study, William Christen, Sc.D., of Brigham and Women’s Hospital, and colleagues “collected data from a cardiovascular disease trial involving more than 5,200 women over 40 who reported they did not have” AMD at the start of the study. The “women had been randomly assigned to take either a daily combination of folic acid, B-6, and B-12 supplements, or a placebo.”
Over seven years, “55 cases of” AMD “were confirmed in the vitamin group,” compared to 82 cases “confirmed in the placebo group.” In other words, women “who took the supplements had a 41 percent lower risk of being diagnosed with” AMD.
AMD “is the leading cause of blindness in people 65 and older, with nearly two million Americans in the advanced stage of the condition,” the Wall Street Journal/AP points out.
AMD “causes a layer of the eye to deteriorate, blurring the center of the field of vision and making it difficult to recognize faces, read, and drive. There’s no cure, but treatment … can slow it down.”
Despite the study’s finding, however, Christen explained that there “were too few cases of the most advanced AMD to make claims about vitamins’ potential benefits.” He emphasized that “it’s too soon to recommend B vitamins to people who want to prevent age-related vision loss.” Instead, he “recommended food sources of B vitamins and folic acid, such as meat, poultry, fortified cereals, beans, nuts, leafy vegetables, spinach, and peas.”
He’s right about using whole and fresh foods as the primary way to get these nutrients, but the other side of the coin is that they are very inexpensive and at these recommended doses do no harm.
Bloomberg News explains that AMD “is caused by damage to the arteries that carry blood to the retina. Folic acid and vitamins B6 and B12 may lower the risk for the disease, Christen said, because they reduce blood levels of homocysteine, an amino acid that contributes to plaque buildup in the arteries.” Study participants “who received the supplements had about an 18 percent lower level of homocysteine than those given the placebo, Christen said.”
The study, led by Yikyung Park, a staff scientist at the US National Cancer Institute, involved “293,907 men and 198,903 women,” MedPage Today added.
“Half of the men and 57 percent of the women reported taking calcium-containing multivitamins, and 14 percent of the men and 41 percent of the women reported using calcium supplements. During a mean follow-up of seven years, the authors identified 36,965 cancers in men and 16,605 cancers in women.”
Park and his colleagues found “that total calcium intake was not associated with a lower risk of cancer in general in men, but women who got up to 1,300 milligrams of calcium per day had a lower risk of cancer overall,” WebMD reported.
“However, total calcium intake from both food and supplements was linked to a lower risk of colorectal cancer and other cancers of the digestive system in both men and women.”
The men “who got the highest levels of total calcium per day through food and supplements had a 16 percent lower risk of these cancers than those who got the least amount per day.”
The women “who get the most calcium per day had a 23 percent lower risk than those with the least reported intake per day.” HealthDay , the Los Angeles Time Booster Shots blog, and the UK’s Press Association also covered the story.
So, rather than taking a multivitamin, you want to be sure to first improve your nutrition — especially increasing your intake of fruits and vegetables. Second, if you want to consider supplementation, consider these three B vitamins, calcium, and vitamin D.
Your doctor can now do a blood test to check your vitamin D levels. Or, you can take 800 – 1000 IU per day.
If you take a calcium supplement, it should be synthetic calcium carbonate. The natural calciums — coral, bone meal, dolamite earth, and oyster shell — should not be taken as they can be laced with the heavy metal, lead.
Also, calcium is best absorbed when taken with food. If you take the recommended 1200 mg per day, take it in two divided doses, as the body cannot absorb more than 600 mg per dose.
The dosages of the B vitamins for the study were folic acid, 2.5 mg per day, vitamin B6 (pyridoxine hydrochloride), 50 mg per day, and vitamin B12 (cyanocobalamin), 1 mg (1000 mg) per day.
To find brands that are safe and reliable, consider checking out the reports on each at www.ConsumerLab.com.