Vitamin D Deficiency

Written by Dr. Steve Chaney on . Posted in Health Current Events, Healthy Living, Supplements and Health, Vitamins and Health

What Is The Real Vitamin D Story?

Author: Dr. Stephen Chaney

 

Vitamin DIf you are like most people, you probably don’t know what to believe about vitamin D deficiency. Some experts tout vitamin D as a miracle nutrient that will help you lead a longer, healthier life. They leave you with the impression that everyone should be supplementing with vitamin D.

Other experts tell you that the supposed benefits of vitamin D are all hype. They tell you not to waste your money on vitamin D supplements.

When you pull back the curtain and look at the clinical studies behind the headlines, a pattern begins to emerge.

Most of the studies that support a role for vitamin D in preventing heart disease, preventing cancer and extending life have been population studies. They have compared populations with low vitamin D intake with populations with adequate vitamin D intake. While population studies are good for suggesting associations, they have their limitations:

  • Population studies are good at suggesting associations, but they do not prove cause and effect.
  • With population studies it is also very difficult to eliminate what scientists call “confounding variables”. Let me give you an example. Suppose someone had low 25-hydroxyvitamin D levels in their blood because they sat around all day watching TV and never got out in the sun. If they got sick you wouldn’t really know whether it was due to low 25-hydroxyvitamin D levels or due to inactivity. In this case, inactivity would be a confounding variable.

On the other hand, most of the studies that fail to find any benefit of vitamin D are double blind, placebo-controlled intervention studies in which one group was given supplemental vitamin D and the other group was given a placebo. While these studies are considered the most reliable clinical studies, they have their limitations as well.

  • In the case of vitamin D many of these studies were done with a cross section of the population in which most of the participants already had adequate blood levels of 25-hydroxyvitamin D at the start of the study. Those studies are incapable of telling us whether correcting a vitamin D deficiency would have been beneficial.
  • Even when the intervention studies focus on participants with low vitamin D status at the start of the trial they have another significant limitation. They are all short term studies. Typically, the best of these studies last no more than a couple of years. Longer term studies are far too expensive. In contrast, diseases such as heart disease and cancer take decades to develop. A one or two year intervention with vitamin D simply may not be sufficient to correct the damage caused by decades of vitamin D deficiency

This is the current dilemma that is creating all of the confusion in the vitamin D story. For the most part, population studies and intervention studies are coming to very different conclusions. And both kinds of studies have inherent limitations that are difficult to overcome.

Fortunately, a new kind of clinical study has been developed in recent years that overcomes the limitations of both population studies and intervention studies.

A New Kind of Clinical Study

Bad GenesThe new approach is something called mendelian randomization. I apologize for the scientific jargon, but let me explain. In this case you are separating your population based on genetic variation rather than on the basis of biochemical or behavioral differences.

 

For example, in the clinical study I will describe in a minute the population was separated into groups based on genetic variations in the DHCR7 and CYP2R1 genes. The first gene is involved in the biosynthesis of cholesterol, which is a precursor of vitamin D, and the second gene converts vitamin D to 25-hydroxyvitamin D. Both genes affect blood levels of 25-hydroxyvitamin D.

This kind of study has several unique strengths:

  • Genetic variations are unaffected by confounding variables such as sun exposure, obesity, smoking, inactivity, and poor diet. If the study population is large enough, those confounding variables will be equally distributed among groups that are selected solely on the basis of genetic variations.
  • These studies are long term by definition. If someone has a genetic variant that lowers their 25-hydroxyvitamin D level, it will do so for their entire lifetime. They can increase their vitamin D status by sun exposure, for example, but their blood levels of 25 hydroxyvitamin D will always be less than someone with equal sun exposure who does not have that genetic variant.
  • Because these studies reflect lifelong exposure to 25-hydroxyvitamin D they are ideally suited for measuring the effect of vitamin D status on mortality and diseases that take decades to develop.

Do Vitamin D Genes Affect Mortality?

This study (S. Afzal et al, The British Medical Journal, 2014;p 349:g6330 doi: 10.1136/bmj.g6330) combined the data from three clinical studies conducted in Copenhagen between 1976 and 2013. The age of the participants ranged from 20 to 100 years and the follow-up was 6-19 years. 95,766 participants in these studies were genotyped for variants in the DHCR7 and CYP2R1 genes which were known to affect 25-hydroxyvitamin D levels. 35,334 of those participants also had blood 25-hydroxyvitamin D levels determined. By the end of the study 10,349 of the participants had died.

  • The individual genetic variants included in this study caused a relatively small (1.9 nmol/L) decrease in blood levels of 25-hydroxyvitamin D. However, because this was a very large study and the participants with those genetic variants were exposed to lower 25-hydroxyvitamin D levels for their entire lifespan, the decreased 25-vitamin D levels were associated with significant increases in all cause mortality and cancer mortality, but not with increased cardiovascular mortality.
  • When they extrapolated to a genetically caused 20 nmol/L decrease in 25-hydroxyvitamin D, the decrease in 25-hdroxyvitamin D was associated with a 30% increase in all cause mortality and a 30% increase in cancer mortality.

What Kind Of Studies Are Needed Next?

The authors noted that this is the first study of its kind, so it obviously needs to be confirmed by other large mendelian randomization studies that test the link between vitamin D status and mortality.

Ideally, it should also be verified by double blind, placebo controlled intervention studies, but that may not be possible. If one really wanted to verify this study, the intervention study should start with a population group with 25-hydroxyvitamin D levels at least 20 nmol/L below what is considered adequate and provide them with enough supplemental vitamin D to increase their 25-hydroxyvitamin D to the adequate range. That is difficult, but doable.

However, the intervention study would also need to be long enough (decades perhaps) to prevent cancer from developing. That kind of study will probably never be done.

 

The Bottom Line

  • The relationship between vitamin D status and mortality has been investigated with a new type of clinical study based on what is called mendelian randomization. Population groups were segregated based on genetic variations in two genes that affect blood 25-hydroxyvitamin D levels (a measure of vitamin D status).
  • This study concluded that a genetically determined decrease of 20 nmol/L in blood 25-hydroxyvitamin D was associated with a 30% increase in all cause mortality and a 30% increase in cancer mortality, but had no significant effect on cardiovascular mortality.
  • This kind of study is particularly strong because it measures the affect of lifelong exposure to 25-hydroxyvitamin D. This is important when assessing the effect of vitamin D status on mortality and diseases such as cancer that take decades to develop. In contrast, the double blind, placebo controlled intervention studies that are consider the “Gold Standard” for clinical studies may be too short term to adequately assess the effect of vitamin D status on cancer or all cause mortality.
  • This study supports the benefit of maintaining optimal vitamin D status, but it is the first clinical study of its kind and needs to be confirmed by other studies.
  • In the meantime, there is no harm to in maintaining your blood levels of 25-hydroxyvitamin D in the optimal range through diet, sun exposure and supplementation. This study suggests it just may help you live a longer, healthier life.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

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Comments (1)

  • Doreen Harrison

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    Love your newsletter, Health Tips From The \professor. I am on you list and want to continue to be so. Thank you for the work you do. I would like to include some of your work in my monthly newsletters if that is OK with you,

    greetings from Canada

    Doreen

    Reply

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Latest Article

How to Choose the Right Pillow

Posted April 17, 2018 by Dr. Steve Chaney

Wake Up Each Morning Pain Free

Author: Julie Donnelly, LMT – The Pain Relief Expert

Editor: Dr. Steve Chaney

 

how to choose the right pillow without headachesThe way you sleep is often a key to discovering the cause of headaches and more. If you wake up with neck pain, a headache, or you suffer from ringing in your ears, dizziness, or ear pain, there is a good possibility that it may be caused by the way you are sleeping. Your pillow may be the culprit.  But if you need to know how to choose the right pillow for you, it’s easy.   It just takes a little “investigation.”

 

How to Choose the Right Pillow if You Sleep On Your Side

Your head, neck, and spine need to always stay in a nice straight line, just as it is when you are standing up, but that takes a little thought and understanding of the way you sleep.  So, get comfy in your bed and then notice how your head is resting.

how to choose the right pillow to sleep painfreeIf you sleep on your side, your pillow needs to be just the right size, so your head doesn’t point down toward the mattress (your pillow is too soft) or up to the ceiling (your pillow is too thick). Either of these positions will make the muscles on the side of your neck stay in the contracted position for hours and pull your vertebrae in that direction, especially when you try to turn over to your other side.

Your SCM Muscle May Cause Serious Problems

You also need to notice if you turn your head a bit, especially if you are turning into your pillow or turning your head up toward away from your pillow. In either of these two cases you will be causing your sternocleidomastoid (SCM for short) to be held shortened for hours.

Your SCM originates on your collarbone and inserts into the bone behind your ear.  When it contracts you turn your head to the opposite side. However, if the muscle is tight (for example, when you’ve held your head turned toward one side for an extended period of time) and then you bring your head back so you are facing forward, the tight muscle will pull on the bone behind your ear and cause havoc.

The symptoms for a tight SCM are tinnitus (ringing in the ear), dizziness, loss of equilibrium, ear pain, headaches, pain in the eye and around the skull, pain at the top of the head, and even pain in the throat. Amazing! What’s even more amazing is that it’s rare that this muscle is considered when a medical professional is searching for the cause of your symptoms.

These are the things to know when considering how to choose the right pillow if you sleep on your side.

How To Choose The Right Pillow If You Sleep On Your Back

how to choose the right pillow for sleeping on your backIf you sleep on your back, your head should be on the mattress (not propped up with a pillow) and you should have a tiny support (like a folded washcloth) under your neck.  Or, you can have a wedge pillow that starts at your mid-back and gently raises your entire trunk and head up while still allowing your head and back to be in a straight line.

It’s always a challenge for people who toss and turn during the night, sometimes on their side and sometimes on their back.  The best thing I’ve found for this situation is to have the pillow below shoulder level so when you turn on your side your shoulder will automatically slide to the edge of the pillow while still supporting your head properly, and when you turn onto your back, the pillow will start at shoulder level so your head and neck are supported, but your head is being pushed in a way that causes your chin to move down to your chest.

hip pain causes and treatment pain freeIt’s tricky, but I can personally attest to the fact that it will work.  I can always tell when I’ve had my head tilted (I toss and turn during the night) because I will wake with a headache. When that happens I’m grateful that I know how to self-treat the muscles of my neck and shoulders so the headache is eliminated quickly.  If you already have Treat Yourself to Pain Free Living,  you can self-treat all your neck and shoulder muscles to release the tension.

How To Choose The Right Pillow If You Sleep On Your Stomach

If you sleep on your stomach, this is the one position that is so bad that it behooves you to force yourself to change your position. Your head is turned to the side and held still for hours, putting a severe strain on all your cervical and upper thoracic vertebrae. Not only will this cause headaches, tinnitus, and a list of other pains, but it can cause problems down your entire spine. It can also impinge on the nerves that pass through the vertebrae on their way to your organs.

If you do sleep that way, let me know and I’ll give you some suggestions that work to change your habit of sleeping. It takes time and energy, but the results are worth the effort.

In every case, the way you sleep may cause neck pain that won’t go away until the pillow situation is resolved.

Now you should know how to choose the right pillow for the way you sleep.

Wishing you well,

Julie Donnelly

About The Author

julie donnelly

Julie Donnelly is a Deep Muscle Massage Therapist with 20 years of experience specializing in the treatment of chronic joint pain and sports injuries. She has worked extensively with elite athletes and patients who have been unsuccessful at finding relief through the more conventional therapies.

She has been widely published, both on – and off – line, in magazines, newsletters, and newspapers around the country. She is also often chosen to speak at national conventions, medical schools, and health facilities nationwide.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

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