Be sure to talk to your doctor about whether vitamin D2 or D3 is more appropriate for you. (D2 is plant-based and more often prescribed by health care providers; D3 is animal-derived and more common over the counter, experts from the Cleveland Clinic explain.) And don’t forget to ask whether vitamin D might affect medications you’re currently taking. Some cholesterol-lowering statins like atorvastatin (brand name Lipitor) may not work as well if you take vitamin D supplements. Similarly, the weight-loss drug orlistat can reduce the amount of vitamin D your body absorbs from food and supplements, according to the NIH.
Your health care provider can also advise you on how much vitamin D to take. Some reports published in the last 10 years have advocated supplementing with up to 2,000 IU of vitamin D daily. “But more recent clinical trials suggested that amount of intake does not show benefits (no harms either), so it may not be the best generic approach for everybody,” Chan says.
Still, excessive doses — the daily upper limit for adults is 100 mcg/ 4,000 IU — can do terrible things to the body: vomiting, confusion, dehydration, muscle weakness and more. Extremely high levels of vitamin D can lead to kidney failure and death.
Remember how aging makes it harder for the body to use calcium? And to make vitamin D?
When it comes to vitamin B12, older adults are also at a disadvantage. That’s because aging impacts the body’s ability to absorb this essential nutrient, which plays an important role in regulating blood, nerve and genetic health, according to the NIH.
Older adults who are vegetarian or vegan, who take the antidiabetic medication metformin or who take gastric acid inhibitors to treat certain digestion problems are even more likely to be B12-deficient. And just like with vitamin D, people with Crohn’s or celiac disease are also more likely to have a B12 deficiency.
If you do have a vitamin B12 deficiency — and it’s estimated that up to 43 percent of older adults do — you will be more likely to develop anemia. A B12 deficiency can also lead to neuropathy or nerve damage (which may feel like tingling or numbness in your hands or feet), balance issues, depression, confusion, poor memory and even dementia.
So how much do you need? The NIH recommends that adults get, on average, 2.4 mcg per day of vitamin B12. When it comes to food, you can get what you need from fish, meat, poultry, eggs, milk, clams and beef liver, as well as from some fortified cereals. Many multivitamin supplements also contain this key nutrient, or you can take it on its own.
And there’s no need to worry if your supplement contains a higher dose than what’s recommended. Unlike calcium and vitamin D, “vitamin B12 has not been shown to cause any harm, even at high doses,” the NIH maintains. Just be sure to talk to your doctor about any medications you are on that could interact with a vitamin B12 supplement.
Calcium, vitamin D and vitamin B12 — that’s the very short list of vitamins and minerals older adults may want to consider taking. Many other dietary supplements lack robust data to support their regular use, and in fact, you might want to steer clear of a few altogether.
• Vitamin E: A vitamin E deficiency is rare in most healthy people, according to the NIH, even if your diet is short on the recommended daily amount (15 mg for adults). And while vitamin E that is naturally present in food causes no harm and does not need to be limited, getting too much from a supplement can be dangerous.
For example, high doses of vitamin E in supplement form can increase bleeding risks, especially in adults on blood thinners. Research has also linked vitamin E supplementation to an increased risk of prostate cancer in men. For these reasons, “routine supplementation of vitamin E should be avoided,” Chan advises.
• Vitamin C: Despite popular belief, there’s no solid data to show that loading up on vitamin C will prevent or cure the common cold. It’s a myth. And taking too much vitamin C can cause diarrhea, nausea and stomach cramps. Instead, opt for citrus fruits and vegetables to get the recommended amount needed to support your overall health.
• Folic Acid: For most people, there is no need to take this B vitamin, since many foods, such as cereals, are fortified with folate. “Folic acid deficiency is rare in the United States … its routine use in aging has not been supported by research,” Chan says. (One exception is during pregnancy.)