Vitamin D as a Contemporary Panacea

Does vitamin D ameliorate dysmenorrheic cramps?

Vitamin D may become an important therapeutic adjunct for a variety of disease states. Its deficiency has been studied as potentially contributory in a number of pathologies such as hypertension, heart disease, bone metabolism, renal disease, and even cancer. A recent “Top Paper” has opened a new door to the role of vitamin D in the reduction of uterine prostaglandin synthesis and alleviation of dysmenorrheic cramps.¹

A ROLE FOR VITAMIN D IN RELIEVING DYSMENORRHEA?

Forty women aged 18 to 40 years with dysmenorrhea and a low 25(OH) vitamin D level (lower quartile) were included. They were randomized into 2 groups. Twenty received a single oral dose of cholecalciferol (300,000 IU/mL) 5 days before their next expected menstrual cycle. Twenty did not receive vitamin D.

The primary outcome measure was intensity of menstrual pain as measured by a visual analog scale. The secondary outcome was use of NSAIDs throughout the study (duration of 2 months).

There was a negative correlation between the pain score at baseline and the level of vitamin D (r 5 20.36; P 5 .2). Cramping pain was less in the group treated with vitamin D (P < .001). None of the women who received vitamin D used NSAIDs, but 40% of those who were untreated took at least 1 NSAID.

QUESTIONING THE DATA

Since the number of women in the trial was small, the invited commentary adds to the interpretation²:

•Is the problem studied significant? Dysmenorrhea occurs in 50% of reproductive-age women. It is one of the most common causes of absenteeism from work or school in these women.

•What is responsible for the pain? The most plausible theory implicates prostaglandins that modulate vascular constriction and uterine contraction.

•So what does vitamin D have to do with the problem? In the endometrium, vitamin D decreases prostaglandin synthesis and increases prostaglandin inactivation.
Vitamin D also down-regulates prostaglandin receptor expression.

•Is there a precedent for a vitamin D amelioration of pain through prostaglandin modulation? Although there is not for dysmenorrhea, there is for premenstrual
syndrome, fibromyalgia, and endometriosis.

PRELIMINARY, PROMISING FINDINGS

How can we best capitalize on these preliminary, promising findings?² There is a need for larger trials of longer duration. The trials need a design that answers several pertinent questions:

•How long will a single dose of vitamin D last?

•Will treatment require repetitive dosing?

•Will repeated dosing exceed recommended total doses or cause harm? Women included in the “Top Paper” were in the lower quartile of vitamin D levels.

•Will vitamin D help women with higher baseline levels?

Despite the unanswered questions, this is a promising study for a common and uncomfortable problem.