Vitamins & Supplements Archive

Ask the doctor

Q. Are vitamin supplements (like vitamin D) good for your health, and can you tell me who might benefit from taking the pills?

Q. Why can't doctors decide if vitamin supplements are good for your health, or not?

A. You might think that it would be simple for doctors to determine if vitamin supplements are good for your health. Alas, it's not. Here's why.

Q. Whatever happened to the idea that taking vitamin C could boost your immune system and prevent colds? Is there still a possibility it could work?

A. Vitamin C, also known as ascorbic acid, was promoted as a health supplement for decades, achieving its greatest renown in the 1970s through the writings of scientist Linus Pauling. Despite the excitement about its natural antioxidant function, vitamin C does not appear to prevent colds, and its ability to shorten the duration of colds is minimal. A recent summary of 29 studies involving more than 10,000 people confirmed the lack of benefit of regular vitamin C supplementation.

If you feel run-down, lack of iron is probably not the cause. You can easily get enough of this key mineral in your diet.

Decades ago, advertising for the liquid vitamin and mineral supplement Geritol warned against "iron-poor, tired blood." It's a reference to the fact that red blood cells need iron to make hemoglobin, the molecule that grabs oxygen and transports it around the body.

People with high blood pressure could benefit from a B vitamin known as folate if they are not getting enough from their diets, according to a study in The Journal of the American Medical Association (JAMA).

The study included more than 20,000 adults in China with high blood pressure who had never had a stroke or heart attack. Participants who took folate supplements along with a blood pressure medication had fewer strokes over the four-and-one-half-year trial than those who only took the medication.

Many different medications can potentially harm the liver, so doctors sometimes do liver function tests to ensure safety. The worst-case scenario is liver failure, but when this happens, the cause is usually not prescription medications, but rather the over-the-counter painkiller acetaminophen (Tylenol) or herbal supplements, according to a study in Gastroenterology.

Researchers scrutinized 5.4 million records of patients in the Kaiser Permanente Northern California system from 2004 to 2010. They identified only 62 cases of liver failure, 32 of which were linked to medications. This may not precisely reflect national rates, but it does suggest that liver failure from medications is relatively uncommon.

Green vegetables and citrus fruits are good natural sources of folate.

If you're among the one in three American adults with high blood pressure, be sure you're getting enough of the B vitamin known as folate. Doing so may lower your odds of having a stroke, a new study suggests.

Supplements can plug dietary gaps, but nutrients from food are most important.

The fresh food you eat is loaded with nutrients necessary for good health, such as magnesium, calcium, and vitamins A and C. But many older adults aren't getting enough nutrients from their diets.

Q. Would you suggest I try taking a probiotic supplement for general colon health? I have a sensitive stomach and sometimes suffer from constipation.

A. Probiotics, the beneficial bacteria that live in our intestines and assist in digestion, have gained a lot of support lately. Each week, a new study appears describing health benefits or diseases associated with changes in the so-called microbiome—the diverse community of microorganisms each of us carries inside our body. Still, the benefits of adding probiotics to the intestinal tract are uncertain.

Probiotics have proved helpful in situations where the body's normal, healthy bacteria have been destroyed, such as after taking a powerful antibiotic. Small studies in people with irritable bowel syndrome have suggested that taking probiotics improves pain and diarrhea. The benefit in constipation is less certain, but it's reasonable for you to try taking a probiotic if you are interested.

Q. There seems to be agreement that supplements are worthless in supporting good health. I've been taking a multivitamin for older women for many years. I also take a calcium supplement since I am lactose intolerant. Should I discontinue the multivitamin, the calcium, or both?

A. You are definitely right about the recent consensus that most supplements, and certainly multivitamins, provide very little, if any, benefit to our health. So yes, stop taking the multivitamin. A far more important strategy to maintain good health is eating a diet containing lots of vegetables, fruit, whole grains, unsaturated fats, and small amounts of protein. Our bodies were designed to absorb nutrients from food, and that continues to be the best way to get them in our systems.