Vitamin D3 for Menstrual Cramps
Study: Vitamin D Reduces Menstrual Cramps
Authors: Antonino L, Antonino C, Salvatore B.
Reference: Improvement of Primary Dysmenorrhea Caused by a Single Oral Dose of
Vitamin D3: Results of a Randomized, Double-blind, Placebo-Controlled Study Arch
Intern Med. 2012;172(4):366-367.
Design: A small randomized controlled trial
Participants: Reproductive aged women ages 18-40 with a history of severe
menstrual cramps for at least four consecutive months within the previous six
months, and who hada blood level of vitamin D < 45 ng/mL, were randomized to
receive either vitamin D or placebo.
None of the women were taking calcium,
vitamin D, birth control pills, IUD or other medications within the previous 6
months as well. The study allowed them to take nonsteroidal anti-inflammatory
drugs (NSAIDS) but they were to record their use of these medications.
Study Medication and Dosage: Twenty women received a single high dose of vitamin
D3 of 300,000 I.U. and 20 women received placebo five days before the
anticipated onset of their next menstrual period.
Primary Outcome Measures: The primary measured outcome was the intensity of the
menstrual pain and the secondary outcome was the use of NSAIDS.
Key Findings: After two months/two menstrual periods, the pain scores decreased
41% in the vitamin D3 group and there was no change in the placebo group. The
greatest reduction in pain was seen in the women in the vitamin D3 group who had
the most severe pain at baseline. In addition, none of the women in the vitamin
D3 group needed NSAIDS to manage their pain at one and two months, while 40% of
the women in the placebo group used an NSAID at least one time.
Practice Implications: Acute menstrual pain affects almost half of menstruating
women. The menstrual pain is thought to be triggered by excessive uterine
production of prostaglandins, synthesized from omega-6 fatty acids before
menses, which control vasoconstriction and uterine contractions. It is thought
that vitamin D may act as an anti-inflammatory and may regulate prostaglandin
pathways. What we don't know is for how many menstrual cycles that effect would
last and whether a single high dose of vitamin D helps women who had higher
blood levels of vitamin D. It is interesting that the study participants had
levels below 45 ng/mL, which is not deficient or insufficient; most clinicians
use the cut-off that if below 20 ng/mL one is deficient and below 30 ng/mL one
"We can judge the heart of a man by his treatment of animals." ~Immanual Kant~