Once again a study finds health problems from supplements. This time, researchers found that several bodies of evidence (the long-running American Nurses' Study and two studies in Norway) found a higher risk of hip fracture in postmenopausal women who took high doses of both vitamin B6 and B12. Interestingly, B12 alone seemed to not be associated with problems. And only getting the vitamins from foods was totally fine.
Yes, taking supplements is highly popular, but many studies are finding adverse effects. As the researchers point out in the journal article: "Both insufficient and excess intakes of a nutrient may be harmful. According to randomized clinical trials (RCTs), high-dose vitamin supplementation may lead to unexpected adverse effects."
The researchers also point out that studies find that vitamin B supplementation has not had a preventive effect on cardiovascular diseases (heart disease) and cancer. Also, taking high doses of vitamin B12 and folic acid supplements has not shown a fracture-preventing effect in studies. And now this finding of a combination of high dose vitamin B-6 and B-12 is associated with an almost 50% higher risk of hip fracture in postmenopausal women. Uh-oh.
So instead of taking supplements, focus on a good diet with a wide variety of foods. Only take (high dose) supplements if there is a known deficiency, and not "just in case".
Excerpts from Medical Xpress: Too much vitamin B can cause hip fracture
Many healthy individuals take high doses of vitamin B supplements. They take them to be on the safe side, thinking that it must be good for their health. The scope of this varies greatly from country to country. It is not common to sell high doses of vitamin B in Norway, but they are nevertheless easy to obtain via the Internet.
However, the high doses have no health-enhancing effect on otherwise healthy people. You only need to take supplements when you have a vitamin B deficiency.
A new study shows that there is an increased risk of hip fracture in women who take high doses of vitamin B6 combined with high doses of B12.
Professor Haakon E. Meyer and his partners at Harvard analysed data from the American Nurses Health Study. The study comprised more than 75,000 American women.
The findings were made in a so-called cohort study. This is a type of study in which researchers follow a group over a long period of time and see who develops diseases or injuries. The data in the study were collected over a period of more than 30 years. The women in the study methodically reported their diet and dietary supplements.
"The study is transferable to Norway, even though American women use a good deal more supplements than their Norwegian counterparts," says Professor Haakon E. Meyer.
"We suspected this when we re-analysed data from two major Norwegian studies in 2017," Meyer says. In these studies, participants were given either high doses of vitamin B or a placebo. Surprisingly, people who received high doses of vitamin B6 and B12 in combination had a significantly increased risk of hip fracture. This finding was confirmed in the new American study.
B12 alone does not result in increased risk—Some elderly people need extra vitamin B12 supplements, and there is no evidence that vitamin B12 alone results in increased risk of hip fracture, Professor Meyer points out.