However Large randomized clinical trial The last few years have shown that vitamin D is not the panacea some believed to be. Bottom Line: The majority of Americans already get all the vitamin D they need from their diet and the sun.
Should You Spend Money on Supplements? For most healthy adults the answer is no. Vitamin needs are low to moderate, more is not necessarily better.
Many people are confused by the changes in vitamin D. To understand how this happened, let’s start with the difference between an observational study and a randomized trial. Randomized trials are experiments that change people’s behavior, much like flipping a coin to determine who takes a vitamin D pill and who takes a placebo to see who does better. . Observation work in the past showed an association between vitamin D levels and risk of chronic disease, but this correlation could not prove causation and may have been due to other factors.
In 2009, a colleague and I began a study to help bridge the gap, looking for clearer answers about whether supplements could prevent heart disease, stroke, and cancer. test vital researchrecruited approximately 26,000 adults and followed them for 5 years. Participants agreed to take placebo or 2,000 international units (IU) of vitamin D per day. I didn’t understand.
Initial results published in 2019 showed no statistically significant reductions in cardiovascular disease or cancer. Other randomized trials have not found clear benefits of vitamin D supplements for these conditions. for example, meta-analysis Twenty-one randomized trials involving more than 83,000 people have examined vitamin D supplements and cardiovascular risk. No single trial showing cardiovascular benefit was found in this analysis.
My colleagues and I have conducted further studies from VITAL showing that vitamin D supplementation does not reduce the risk of cognitive decline, depression, macular degeneration, atrial fibrillation, or several other health conditions. did. Fracture rate — once the most commonly touted benefit of vitamins.
In other words, vitamin D is not a panacea. But it showed promise in two key areas.
At VITAL, we found that vitamin D supplements may help reduce autoimmune disease and advanced (metastatic or fatal) cancer. reduce the risk of developing 22 percent advanced cancer 17 percent (without reducing other cancers). Our team is conducting further research to delve deeper into these findings, investigating whether the effects of vitamin D vary with genetic factors.
Other studies have shown that vitamin D may help improve immune function and reduce inflammation. possible link Between vitamins and better covid results.My colleague and I are leading randomized trial of 2,024 participants nationwide to find out if vitamin D affects likelihood of covid-19 infection, risk of severe symptoms, and long covid onset. The survey results will be published later this year.
In the meantime, as the pandemic drags on, it is reasonable (but not essential) for healthy adults to supplement with low to moderate amounts of vitamins: about 1,000-2,000 IU per day. It has been shown to be safe. Very high doses, or “megadoses” (e.g., >6,000 IU daily) have not been studied long-term and have been associated with high blood calcium levels, kidney stones, and may increase the risk of other health problems.
If you are part of a group at high risk for vitamin D deficiency, talk to your doctor. I take supplements and have my blood levels of vitamin D tested. This includes people living in nursing homes who have little exposure to sunlight. People with certain dietary restrictions, such as severe lactose intolerance; People with malabsorption conditions, such as Crohn’s disease or celiac disease; People undergoing treatment for osteoporosis or other bone health problems.
Otherwise, if you feel good and healthy, testing for vitamin D is probably a waste of money. U.S. Preventive Services Task Force didn’t find enough evidence We recommend regular screening because no studies have clearly shown that it is associated with better health outcomes. deficiency Also, recommended blood levels vary by organization, country, and laboratory, further questioning the usefulness of the test. National Academy of Medicine recommends levels of 20 ng/ml or higher, although some organizations recommend higher levels.
If you’re concerned about your vitamin D levels, but aren’t in a high-risk group, try increasing your intake by taking a few simple steps instead.
of national academy recommends 600 IU of vitamin D per day for adults up to age 70, and 800 IU for those over 70. In the United States, foods such as dairy products, cereals, and orange juice are often fortified with vitamin D (countries that do not fortify foods have higher rates of vitamin D deficiency). food to buy. Wild mushrooms and oily fish such as salmon, sardines and tuna are other sources.
Also, a 15-minute walk at noon a few times a week usually provides enough sunlight for your skin to synthesize vitamin D. Exercising outdoors, such as playing sports or jogging, is even better for your health. Wearing sunscreen reduces the absorption of sunlight, but prolonged exposure to the sun is important to prevent skin cancer and premature skin aging.
It’s much easier to take a pill than to exercise and eat healthy outdoors, but the latter two can help you stay fit and reduce your risk of cardiovascular disease, cancer and diabetes. I have. Taking supplements is by no means a substitute for a healthy diet and lifestyle.
