One single dose of calcitriol, the metabolically active version of vitamin D, followed by ongoing vitamin D supplementation has been shown to prevent the progression of multiple sclerosis, according to new research.
Calcitriol (vitamin D3), is transformed in the liver and kidneys into 25- hydroxyvitamin D (25(OH)D), the non-active ‘storage’ form, and 1,25-dihydroxyvitamin D (1,25(OH)2D), the biologically active form that is tightly controlled by the body.
Several studies have reported that the D3 form of the vitamin is more potent that D2, with a study led by Robert Heaney, MD, from Creighton University in Nebraska reporting earlier last year that D3 was 87% more potent than D2 (Journal of Clinical Endocrinology & Metabolism, doi: 10.1210/jc.2010-2230).
While our bodies do manufacture vitamin D on exposure to sunshine (UV-B radiation with a wavelength between 290 and 315 nm), the levels in some northern countries are so weak during the winter months that our body makes no vitamin D at all.
Halts Multiple Sclerosis
Writing in the Journal of Neuroimmunology. the US-based team investigated the potential of different combinations of vitamin D therapy had benefit on the course of multiple sclerosis (MS) in a mouse model of the disease known as experimental autoimmune encephalomyelitis (EAE).
Led by Professor Colleen Hayes from the University of Wisconsin-Madison, the team assessed the outcomes of varying combinations of the active vitamin D hormone calcitriol and vitamin D3 from dietary supplements — finding that an initial single oral dose of calcitriol followed by daily supplementation with dietary vitamin D3 “was a runaway success.”
“One calcitriol dose plus vitamin D3 supplementation sustainably reversed clinical EAE signs without inducing hypercalcemia,” explained the research team – noting that the protocol ‘rapidly and transiently’ increased T regulatory (Treg) immune cells in the central nervous system of the mice and sustainably reduced CNS CD4+ T cells, and spinal cord and optic nerve pathology, “thereby promoting clinical recovery.”
“All of the animals just got better and better, and the longer we watched them, the more neurological function they regained,” explained Hayes.
In the current study, which was funded by the National Multiple Sclerosis Society, Hayes’ team compared various vitamin D-based treatments to standard MS drugs. In each case, vitamin D-based therapy was found to be bettere than the drug alternative, the authors revealed — noting that the mice that received them showed fewer physical symptoms and cellular signs of disease.
In the first part of the study Hayes and his colleagues compared the effectiveness of a single dose of calcitriol to that of a comparable dose of a glucocorticoid, a drug that is currently given to MS patients who experience a bad neurological episode.
Calcitriol came out ahead, inducing a nine-day remission in 92% of mice on average, versus a six-day remission in 58% for mice that received glucocorticoid.
“So, at least in the animal model, calcitriol is more effective than what’s being used in the clinic right now,” says Hayes.
Next, the team tried a weekly dose of calcitriol — finding that such a strategy could reverse the disease and sustained remission indefinitely.
However, Hayes warned that calcitriol can carry some strong side effects and is a “biological sledgehammer” that can raise blood calcium levels in people.
Because of this, they tried a tried a third regimen: a single dose of calcitriol, followed by ongoing vitamin D supplements in the diet.
This “was a runaway success,” she said. “One hundred percent of mice responded.”
Hayes believes that the calcitriol may cause the autoimmune cells attacking the nerve cells’ myelin coating to die, while the vitamin D prevents new autoimmune cells from taking their place.
While she said that she is excited about the prospect of her research helping MS patients someday.
“So it’s not certain we’ll be able to translate [this discovery to humans],” she said. “But I think the chances are good because we have such a broad foundation of data showing protective effects of vitamin D in humans.”
The next step is human clinical trials, a step that must be taken by a medical doctor, a neurologist, she said. If the treatment works in people, patients with early symptoms of MS may never need to receive an official diagnosis.
“It’s my hope that one day doctors will be able to say, ‘We’re going to give you an oral calcitriol dose and ramp up the vitamin D in your diet, and then we’re going to follow you closely over the next few months. You’re just going to have this one neurological episode and that will be the end of it,'” said Hayes. “That’s my dream.”
How To Make Sure You’re Getting Enough Vitamin D
Sunlight contains ultraviolet (UV) rays that come in three different lengths: UV-A, UV-B, and UV-C.
UV-B rays are the ones that are capable of producing vitamin D in your body by acting on cholesterol found in your skin.
To make vitamin D, you need UV-B rays to come into direct contact with your skin. UV-B rays cannot penetrate glass, so you don’t make any vitamin D while you’re sitting in a car or by a window at work or at home.
But creating enough vitamin D in your body isn’t as simple as getting a certain number of minutes of sunlight exposure every day because the number and intensity of UV-B rays that reach your skin and lead to vitamin D production is affected by a number of different factors, the main ones being:
- Your Skin Color
Lighter skin color allows deeper penetration by UV-B rays, which decreases the amount of sunlight exposure needed for adequate vitamin D production. If you have darker skin, it’s harder for UV-B rays to penetrate your skin and create vitamin D, which means that you need greater exposure to sunlight than someone with lighter skin.
If you live above 35 degrees latitude north or below 35 degrees latitude south, you receive little to no UV-B rays from some point in autumn to some point in spring. During this time, your body has to rely on the vitamin D that it has created during warmer months, or on intake of vitamin D through food and supplements.
- Altitude and Latitude
The further north or south you live from the equator, the less exposure you have to UV-B rays.
The higher you live above sea level, the greater exposure you have to UV-B rays.
- Pollution and Clouds
Both decrease the number of UV-B rays that reach you.
- Your Age
With each passing year, natural degenerative changes that occur in your skin make it harder for UV-B rays to convert cholesterol in your skin into vitamin D. It’s a known fact that elderly people need to rely more on food sources than sunlight for their vitamin D. At 70 years of age, the average person has approximately 30% of the capacity to generate vitamin D from sunlight that a 20-year old has.
How Much Vitamin D Do You Need for Your Best Health?
The optimal range is somewhere between 50 and 60 ng/ml (125 to 150 nmol/l). To convert ng/ml to nmol/l, simply multiply by 2.5.
Unfortunately, the only way to know where you’re at is to ask your doctor to include 25 (OH) D, also known as 25-hydroxy D, with your blood work during your next checkup. Some labs test for 1,25 hydroxy D, which isn’t as accurate a marker of your vitamin D status as 25 hydroxy D, so be sure to specifically ask for 25 hydroxy D.
You want your 25 hydroxy D level to be at least 30 ng/ml (75 nmol/l), but again, based on the research that I have reviewed, mainly that of Dr. Michael Holick, the optimal range appears to be 50 to 60 ng/ml. Some prominent physicians and vitamin D experts feel that one can go even higher, even up to 80 ng/ml. But my suggestion is to err on the side of caution and aim to be in the 50 to 60 range.
The 50 to 60 range is based on numerous studies that show strong relationships between these levels and reduced risk of a wide variety of chronic diseases and increased lifespan. This range is also based on the 25 hydroxy D levels of healthy people living in areas of the world (tropical and subtropical regions) where it’s quite common to receive more than enough sunlight exposure to ensure regular vitamin D production.
But here’s an important point that you want to keep in mind: When sunlight creates vitamin D in a healthy person and that person’s 25 hydroxy D is in the optimal range, that person is almost certainly benefiting from other natural compounds that are generated with sunlight exposure. Dr. Holick calls these other compounds “photo products,” and he and his team are currently researching the makeup and benefits of these photo products.
Put another way, establishing optimal vitamin D status mainly via healthy sunlight exposure may provide more health benefits than establishing optimal vitamin D status mainly via foods and supplements. Correct usage of foods and supplements only gives you the right amount of vitamin D – they don’t generate the photo products that sunlight does.
At the same time, it’s worth remembering that even responsible exposure to sunlight comes with some undesirable effects, like premature aging of skin and possibly increased risk of non-melanoma skin cancers, depending on your history of sunlight exposure.
So it’s too early to say which is more desirable between getting vitamin D mainly from sunlight vs. mainly from foods and supplements.
What we do know for sure is that keeping your 25 hydroxy D level somewhere between 50 and 60 ng/ml, possibly even up to 65 ng/ml can significantly decrease your risk of all types of disease and increase your lifespan. And a wise approach is likely getting vitamin D from a combination of responsible sunlight exposure and foods and supplements that come with vitamin D.
Vitamin D is best obtained by sunlight, but if pursuing supplementation, look for high quality vitamin D3 cholecalciferol and stay away from those with dangerous preservatives such as potassium sorbate.
Journal of Neuroimmunology
Mae Chan holds degrees in both physiology and nutritional sciences. She is also blogger and and technology enthusiast with a passion for disseminating information about health.