Vitamin D and Menstrual Cramps

March 05, 2012

Vitamin D and Menstrual Cramps 

 Reference Lasco et al Archives Int Med, Feb 27th 

 Menstrual cramps are the bane of many women causing pain that can last days.   The thought is that the smooth muscles of the uterus are contracting in response to high doses of localized prostaglandins.  Those prostaglandins are inhibited by ibuprofen and other NSAIDs, which block the production of prostaglandins.    Easy enough but not always satisfactory, and NSAIDs can have side effects too.   Because vitamin D reduces the synthesis of prostaglandins, a beneficial effect of vitamin D in the uterus was considered pathophysiology possible.  It was worth a try.

 That makes this study from Italy somewhat unique.  The study compared Vitamin D to placebo.   But it wasn’t just any dose of Vitamin D.  The authors gave 300,000 IU of Vitamin D in a single dose approximately 5 days before the anticipated menstrual cycle.   The results were somewhat surprising.  The women getting the D had a 41% decline in their pain scores and didn’t have the need to take any medication for their pain.  The study only lasted two months so really didn’t have the ability to predict long-term usefulness, or safety.  It also only had 20 women in each group, so it wasn’t a huge study.  

But this has been an intractable problem for many women and this is a pretty nice sign of relief. The real question is safety and long-term use of this type of dose.  That hasn’t been resolved.  The study has been widely reported and many are asking whether it is safe to do long term.  The study does tell us a couple of interesting things.  One, a single dose of D in a small group of people didn’t come up with any side effects.   In England, a single annual 600,000 IU dose given by injection in nursing homes has been found to be safe.   Three hundred thousand units once a month would be the equivalent of 10,000 IU a day on a regular basis.  

That daily dose should make a blood level of about 80 ng in many folks, below the usually toxic level of 150 ng but well above the 50-60 ng humans naturally make on their own.  (See last week’s News)  We do know that a single dose of 100,000 IU will raise your blood level about 14 ng in just 24 hours and that 100,000 IU once a month has much the same effect as taking 3,000 IU a day which is a roughly comparable dose.   We also know that your fat tissue will store D and then gradually release it as you need it back. Can we recommend this for long-term use?  I don’t think so. Not quite yet.  What might be a reasonable and safer question would be to take enough D to get your blood level into the 60-80 range under the supervision of your doctor.    If that takes care of your menstrual cramps, then maybe we have another way of treating menstrual cramps that isn’t quite so “unexplored” as the single large dose. 

 WWW.  What Will Work for Me.  I get questions all the time as to the safety of D in single dose.  This gives us a new indication that a single large dose is safe.  It doesn’t say repeated large doses are safe every month.  But it does raise a new venue for possible relief for a devilish problem that affects as many as 50% of us! 

Pop Quiz

1.    What was the procedure to reduce menstrual cramps?           Answer:   5 days before the anticipated cycle, a single dose of 300,000 iu of D given orally

2.   What was the result of this treatment?                     Answer: a 41% reduction in pain scores and no indication of toxicity.

3.   What guidance do we have about dosing of D and blood levels?                  Answer:  A single dose of 100,000 IU of D will increase serum D by 14 ng in 24 hours.  

4.   What was the proposed means by which Vitamin D would work in this context?            Answer:  It is well known that cramps are caused by too many prostaglandins and Vitamin D is known to reduce their production.  There you have it. 

 Written by John E Whitcomb, MD  Brookfield Longevity and Healthy Living Clinic, 17585 W North Ave, Suite 160   Brookfield, WI 53045   262-784-5300