Vitamin D and pain

[Guest guest]

Docs:

Good article on Vitamin D and pain.

Lyndon McGill, D.C.

EvolvHealth Wellness Advisory Council Member

Salem, Oregon

www.SalemSpineClinic.com

www.EvolvingDaily.com

Can Vitamin D Treat Pain?

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February 27, 2012 — Women with dysmenorrhea who take a single

high dose of vitamin D suffer much less menstrual pain and have no

need of pain medications for any reason for up to 2 months, a new

study has found.

“To our knowledge, this is the first study investigating the

effect of a single high dose of vitamin D in primary

dysmenorrhea,” wrote the study authors, led by Antonino Lasco, MD,

from the Department of Internal Medicine, University of Messina,

Italy.

“Our data support the use of cholecalciferol in these patients,

especially when exhibiting low plasmatic levels of 25(OH)D

[25-hydroxyvitamin D],” they write.

The study is published February 27 in the Archives of

Internal Medicine.

Pain Trigger

Dysmenorrhea affects almost one half of menstruating women. The

pelvic pain is believed to be triggered by excessive uterine

production of prostaglandins, synthesized from omega-6 fatty acids

before menses, that control vasoconstriction and uterine

contractions.

According to the study authors, vitamin D may act as an

anti-inflammatory and may regulate the expression of key genes

involved in the prostaglandin pathway, causing decreased

biological activity of prostaglandins.

The study included 40 women aged 18 to 40 years who had

experienced at least 4 consecutive painful menstrual periods in

the past 6 months and had a 25(OH)D serum level below the upper

limit of the lowest quartile (<45 ng/mL). They were not taking

calcium, vitamin D, oral contraceptives, or other medications, and

they had not used an intrauterine contraceptive device during the

previous 6 months.

The participants could use other means of birth control, however.

They were also allowed to use nonsteroidal anti-inflammatory drugs

(NSAIDs) as needed, but they had to record their use of these

agents.

The women were randomly assigned to receive a single oral dose of

300,000 IUs of vitamin D (cholecalciferol) or placebo 5 days

before the time they expected to begin their next menstrual

period.

The primary outcome was intensity of menstrual pain as measured

by a visual analog scale. The secondary outcome was use of NSAIDs.

After 2 months, baseline pain scores decreased 41% among women in

the vitamin D group; there was no difference in scores among women

taking placebo (P < .001). The greatest reduction in

pain was among women in the vitamin D group who had the most

severe pain at baseline (r = -0.76; P < .001)

During the study, none of the women in the vitamin D group needed

NSAIDs to manage pain at 1 and 2 months, whereas 40% of those

taking placebo used an NSAID at least once (P = .003).

Implications for Chronic Pain?

In an accompanying commentary, R. Bertone-, ScD,

from the Division of Biostatistics and Epidemiology, University of

Massachusetts, Amherst, and JoAnn E Manson, MD, from the Division

of Preventive Medicine, Department of Epidemiology, Brigham and

Women’s Hospital, Harvard Medical School, Boston, Massachusetts,

said the study provides support for larger randomized trials of

vitamin D for treating pain-related conditions in women.

Chronic widespread pain and fibromyalgia syndromes are more

prevalent in women, "likely owing to the influence of sex steroid

hormones," they write.

This future research, they write, must address several key

issues.

"First, it is important to know how long reductions in pain

associated with a single high-dose vitamin D therapy would persist

and how often treatment would need to be repeated," the

editorialists write. They point out that each dose would need to

be effective for a lengthy period for average daily intake to

remain below recommended upper limits.

Because many women will experience dysmenorrhea for several years

until menopause, follow-up of participants in vitamin D trials

must be extended to better evaluate adverse effects and to compare

risks and benefits, they note.

The editorialists also note that it remains unknown whether

vitamin D would improve dysmenorrhea pain in women with higher

25(OH)D levels.

"If these findings are confirmed in future randomized trials,

vitamin D supplementation may become an important new treatment

option for women who experience menstrual pain disorders," they

conclude. "In the meantime, encouraging all women to obtain the

recommended dietary allowance for vitamin D (≥600 IU/d for women

of reproductive age), as well as screening for low serum 25(OH)D

levels among women with other risk factors for vitamin D

deficiency, would be a rational interim approach."

Pain Site

Approached for comment, Clifford Lo, MD, PhD, Director, Harvard

Human Nutrition Program, and Medical Education Coordinator,

Harvard Medical School Division of Nutrition, said that although

the numbers were small, there was a convincing difference between

the placebo and vitamin D groups in the study.

However, although it is plausible that vitamin D affects

prostaglandins, the study did not specify which prostaglandin or

which pain site might be involved, said Dr. Lo, whose research

interests include vitamin D metabolism.

The study proposes an interesting possible mechanism, "but that's

certainly not good enough for me to say that this is a good

treatment for pain," said Dr. Lo. "It's very premature to say it's

something we should use."

Pain associated with dysmenorrhea is generally subjective and not

easily measured, he added. It is difficult to make conclusions

about the effect an agent will have on pain when there is "no

convincing biomarker" for the pain, as was the case with this

study, said Dr. Lo.

The 300,000 IU dose of vitamin D used in the study is probably

harmless if taken every month or 2, and even perhaps every week,

but it could cause hypercalcemia if taken daily, said Dr. Lo. The

typical vitamin D dose is 400 to 1000 IU/day.

Dr. Lo pointed out that because the participants in the study had

vitamin D levels below 45 ng/mL, they were not exactly deficient

in vitamin D to begin with. "Most people would say that you're not

deficient until you're below 20 ng/ml," he said. "I would say that

half the American population is below 30 ng/mL."

The study authors and editorialists have disclosed no

relevant financial relationships.

Arch Intern Med. 2012;172:366-367, 367-369.

Medscape Medical News © 2012 WebMD, LLC