From supporting bone health to shoring up your immune system, you’ve heard that vitamin D is one of the most important vitamins you can take.
But the debate over who should take how much is still ongoing, leaving many of us wondering if the recommended daily amount (RDA) for the sunshine vitamin (a measly 800 IUs for most adults) should be our target. Or, maybe we should aim for 5,000 to 10,000 IUs or more, as some doctors and experts recommend.
Well, at least when it comes to warding off the frailty that comes with age, we may have some answers...
Does frailty begin with low levels in middle age?
Research performed by a team at the University of Buffalo specifically set out to look at the issue of frailty due to its likelihood to lead to disability, loss of independence and increased rates of mortality.
They defined frailty as three or more of the following five characteristics:
- Unexpected weight loss
- Weak grip strength
- Self-reported exhaustion
- Low levels of physical activity
- Slow walking speed
Previous research by the team had shown that long-term low levels of the sunshine vitamin in middle age could reduce the capacity for exercise, causing the body to shed muscle and put on fat.
This got the scientists wondering…
If vitamin D is so important for middle-aged people to keep them strong, slim and moving, how much more important could it be at older ages?
So they set up a new study using an aged mice model…
That study, published in the journal Nutrients, revealed that not getting enough vitamin D in older age may drive the development of frailty.
Not only that, but it only took one month with low vitamin D levels to start the spiral into frailty.
Dose matters
There was one more critical finding…
The scientists found that vitamin D only protected the mice from these effects when intake was 5 times higher than the equivalent recommended intake for older adults.
“To slow the progression of frailty, it actually took greater amounts of vitamin D than what is currently considered sufficient for a human,” said lead researcher, Prof. Seldeen.
This means a daily dose of 4,000 IU would be needed to slow the development of frailty in old age.
I guess our questions about whether the RDA for vitamin D is good enough are settled. In fact, many will argue that 800 IU is barely enough for healthy bones.
That's why I'm a fan of a therapeutic serving of 5,000 IU daily. Many physicians suggest that amount to boost low levels, and even just to maintain them.
Many things are working against sufficient vitamin D levels in your body, including:
- Weight. If you are overweight, vitamin D is less bioavailable in your body. Good things happen when you get enough. A 2015 study found that people who were overweight or obese and deficient in vitamin D lost weight once they started taking a vitamin D supplement.
- Toxins. Exposure to endocrine-disrupting chemicals, like BPA from plastics, reduces vitamin D levels in your bloodstream.
- Age. A person over the age of 70 produces 30 percent less vitamin D than a younger person with the same amount of sun exposure.
- Existing conditions, including digestive disorders like celiac disease, chronic pancreatitis, irritable bowel syndrome and Crohn’s disease, cause poor vitamin D absorption.
Make sure your body gets the D it needs.
Sources:
Vitamin D — NHS
Vitamin D Helps the Immune System During Cold and Flu Season — Pharmacy Times
Mayo Clinic Q and A: How much vitamin D do I need? — Mayo Clinic
Very high dosages of vitamin D may delay frailty in old age — MedicalNewsToday
FAQ: Vitamin D and Frailty
What is frailty in older adults?
Frailty is a decline in physical resilience that can make everyday activities harder and increase the risk of disability and loss of independence. Common signs include unintended weight loss, weak grip strength, exhaustion, low physical activity and slower walking speed.
Can low vitamin D contribute to frailty?
Research suggests it may. Vitamin D plays an important role in muscle and bone health, and low levels have been associated with poorer physical function. In the animal study discussed here, vitamin D insufficiency led to declines in grip strength, endurance and other markers of frailty.
Does vitamin D help maintain muscle strength?
Vitamin D supports normal muscle function as well as bone health. Maintaining adequate levels may therefore be especially important with age, when muscle mass, strength and mobility naturally become more vulnerable.
How much vitamin D do older adults need?
Vitamin D needs can vary based on age, blood levels, sun exposure, body weight, diet and health status. Research suggests that some people may benefit from amounts above the standard daily recommendation, particularly when vitamin D levels are low or additional support is needed.
Is 5,000 IU of vitamin D a therapeutic dose?
Yes. A daily intake of 5,000 IU is commonly considered a therapeutic level of supplementation and is often used to help support or restore healthy vitamin D status. Individual needs vary, so vitamin D testing can be useful for determining the most appropriate intake over time.
Why does vitamin D become harder to maintain with age?
The skin becomes less efficient at producing vitamin D from sunlight as we get older. Limited sun exposure, higher body weight, certain digestive issues and other factors can also make it harder to maintain adequate levels.
Can you get enough vitamin D from sunlight alone?
Some people can maintain healthy levels with regular sun exposure, but many cannot. Season, latitude, skin pigmentation, age, sunscreen use, time spent indoors and other factors all affect how much vitamin D the skin can produce.
How can I tell if my vitamin D level is low?
A blood test for 25-hydroxyvitamin D is the standard way to assess vitamin D status. Testing can help show whether your current intake is sufficient and whether additional support may be helpful.
