Don’t be. In this post, I’ll explain what is currently recommended, when it comes to vitamin D for older adults, and why I recommend this to most of my own patients.
I’ll also address some frequently asked questions.
My Recommended Daily Dose for Vitamin D in Older Adults
For most older adults, I recommend a supplement of vitamin D 1000 IU/day.
I do this because:
- For older adults at increased risk for falls, the US Preventive Task Force recommends vitamin D supplementation to help prevent falls.
- The American Geriatrics Society (AGS) recommends that clinicians tell older patients to take vitamin D 1000 IU/day, to help prevent fractures.
I also do this because:
- Many older adults have risk factors for vitamin D deficiency. These include having osteoporosis and spending limited time outdoors.
- Many older adults are at increased risk for falls.
- In the vast majority of older people, taking vitamin D 1000 IU as a supplement every day has very low risk of harm.
Other expert groups have provided similar vitamin D guidance. For instance, in 2010 the Institute of Medicine published a report with age-based Recommended Daily Allowances for vitamin D in “normal healthy persons.” For people aged 1-70, they recommended 600 IU/day. For people aged 71+, they recommended 800 IU/day.
I think either 800 IU/day or 1000 IU/day is fine, but I usually tell people 1000 IU/day, as it’s a nice round number recommended by AGS. I call this the “healthy aging” dose of daily vitamin D.
For people who are already taking a multivitamin or calcium supplement, they should check to see how much vitamin D is already included, as they may already be getting 1000 IU from those supplements.
Frequently Asked Questions about Vitamin D
Which type of Vitamin D should I take?
Most supplements contain vitamin D3, also known as cholecalciferol. Studies suggest that this increases blood levels a little better than vitamin D2 (ergocalciferol).
Both these versions of vitamin D require processing by the liver and kidneys. People with liver or kidney disease may need to get a special type of supplement from their doctors.
Although Vitamin D supplements are usually taken daily, they also come in higher doses, which may be prescribed for weekly or even monthly dosing. (These are available over-the-counter, but I think it’s best to take these under medical supervision.)
Do I need to have my vitamin D blood level checked?
Not necessarily. The AGS consensus statement says that testing vitamin D levels should be unnecessary in most older adults, unless some particular symptom or disease warrants it.
The idea is that if people take a daily vitamin D supplement as recommended above, they’ll be highly unlikely to have a vitamin D level that is too low or too high.
On the other hand, if you have been diagnosed with a serious vitamin D deficiency, your doctor will likely recommend a higher dose of vitamin D supplementation. In this case, most experts recommend a repeat vitamin D blood test after 3-4 months of treatment. For most people, the test would be for the 25(OH)D level. People with certain conditions may require a different type of test.
I do end up checking vitamin D levels sometimes in my practice, because many of my patients have severe osteoporosis, or sometimes an abnormal blood calcium level.
That said, I agree with those who say that vitamin D testing is often overused. But of all the tests and services to overuse, this one strikes me as fairly minor. If you’re worried about overtesting or overtreatment, it’s far more worthwhile to avoid unnecessary scans, procedures, and medications.
Will vitamin D really prevent falls or fractures?
Good question. Some studies have suggested that vitamin D reduces the chance of these serious health events, but these results have been questioned by later studies.
My current take is that vitamin D might help a bit, especially for certain seniors. Since it has low chance of harm and probably helps some people somewhat, I recommend it.
However, I usually tell people to not have overly optimistic expectations of vitamin D’s effects. In most older adults, problems such as pain, fatigue, and/or falls are due to multiple underlying causes, so there’s often no easy fix available.
Will vitamin D prevent dementia, cancer, and/or premature death?
Several studies have identified an association between vitamin D deficiency and diagnoses such as Alzheimer’s disease and cancer. In other words, people with these conditions tend to have low vitamin D blood levels.
But an association isn’t the same thing as causation, so it’s not yet known whether vitamin D deficiency causes these diseases. It’s also not yet known whether taking vitamin D supplements will reduce one’s chance of developing these diseases.
In 2010, the Institute of Medicine concluded “This thorough review found that information about the health benefits [of vitamin D supplementation] beyond bone health—benefits often reported in the media—were from studies that provided often mixed and inconclusive results and could not be considered reliable.”
My take: although the ongoing research on vitamin D is very interesting, I feel it’s unlikely to make practical changes to my practice. Although it’s possible that low vitamin D levels might be a factor in developing certain diseases, it’s probably a small effect. Cancer and Alzheimer’s, after all, generally seem to be the result of lots of little factors — genetics, epigenetics, stress, immune function, nutrition, inflammation, toxins — interacting over time.
Furthermore, taking a daily vitamin D supplement as recommended above should help most people avoid very low vitamin D levels.
I am outside a lot. Do I need a vitamin D supplement?
Hard to say without checking your levels. In general I recommend people take a daily vitamin D supplement no matter how much time they spend outside.
To begin with, it’s usually a good idea to wear sunscreen if you are going to be exposed to UV radiation, because skin cancer is common! Furthermore, even if you are getting enough vitamin D through sunlight or diet, taking a supplement of 1000 IU is unlikely to raise your vitamin D levels to a problematic range.
In my view, people of all ages usually have plenty they can and should do for their health and their lives. Why spend much time figuring out vitamin D? Take whatever vitamin D is recommended for your age (or by your doctor), and focus your energies on getting enough exercise, implementing other healthy habits, taking care of those who need you, and managing any chronic conditions you have.
What should one’s vitamin D level be?
This question has been hotly, hotly debated. At this time, it depends on who you ask.
The Institute of Medicine believes a blood level of 20-40 ng/mL should be adequate. The Endocrine Society, the American Geriatrics Society, and some other expert groups recommend a level of at least 30 ng/mL.
As noted above, the party line — which I consider reasonable — is that most people don’t need their vitamin D level checked. In the absence of certain health problems, a low vitamin D level is unlikely in someone who takes a daily supplement.
I heard that a higher level of vitamin D is better for you. How much is too much?
Again, this depends on who you ask. The American Geriatrics Society says for most people, total vitamin D (from supplements and food) shouldn’t exceed 4000 IU/day.
Research into the risks of too much vitamin D is ongoing. A study of very high vitamin D supplementation (500,000 IU once a year) increased falls and fractures in older adults, so clearly it’s possible to have too much of a good thing.
I have also personally encountered a few patients with high blood calcium levels, who were taking high doses of vitamin D supplements and had fairly high blood levels of vitamin D. (Vitamin D is related to the absorption and metabolism of calcium in the body.) One of them went on to have a heart attack a few months later; his blood level of vitamin D had been about 70 ng/mL. This is a single case, but given that calcium supplements have been linked to heart attacks, I wonder if research won’t eventually confirm a link between high vitamin D blood levels and increased heart attack risk.
My own practice is to caution patients if they are taking daily vitamin D supplements of more than 2000 IU/day in the absence of documented deficiency. I also discuss a reduction in vitamin D supplementation if a patient has a blood level greater than 50 ng/mL.
For more information on vitamin D, here are some useful articles:
- Vitamin D Fact Sheet (for Health Professionals), from the National Institutes of Health Office of Dietary Supplements
- Getting Enough Vitamin D in Later Life, from HealthinAging.org
- Why Vitamin D Has the Medical Establishment Totally Confused, from Vox.com
Questions or comments? Please let me know below.