The U.S. Institute of Medicine recommends that women aged 19 to 50 get 600 IUs of vitamin D a day, with upper tolerable levels of 4,000 IU daily. Higher doses may cause health problems and can damage the heart, blood vessels and kidneys by raising calcium levels in the blood.
A shot of 300,000 IUs every two months would land a woman at an average 5,000 IUs a day - above the tolerable limit.
“I think it would be reasonable if a woman is having severe menstrual cramps to try a moderate dose and see if she gets relief, but stay below what the Institute of Medicine recommends as the higher level,” said Manson.
How To Relieve Menstrual Cramps
- OTC pain relievers such as ibuprofen or naproxen used around the clock at the first sign of your period helps to reduce the severity of cramps in many women by inhibiting the release of prostaglandins.
- Regular exercise such as walking helps to prevent or at least reduce the severity of menstrual cramps for some women.
- Oral contraceptives may effectively reduce or eliminate menstrual cramps for some women; however you should consider the side effects of oral contraceptives before using them to prevent cramps.
- Zinc, calcium, and B vitamins obtained in food and supplements have been found to reduce cramps, bloating and other symptoms.
- Herbal remedies such as Viburnum prunifolium, Scutellaria spp., and Cimicifuga raemosa have an antispasmodic effect that may reduce some menstrual cramps.
- A warm bath filled with aromatherapy or a heating pad on your lower abdomen and back is often helpful for relieving menstrual cramping.
Vitamin D3 supplements usually cost around $10 to $20 for a month’s supply, and Manson said those who want to give it a try could take somewhere between 1,000 IUs and 2,000 IUs a day.
Some research has also suggested that vitamin D deficiencies could be involved in other ailments, such as cancer and autoimmune disorders. Manson and her colleagues are currently running a large trial to see if taking the vitamin - with or without fish oil - can help stave off cancer or heart disease in healthy men and women.
But she also warned that some studies had shown that when it comes to vitamins, more isn’t always better. For instance, high doses of beta-carotene may up the risk of lung cancer, whereas too much vitamin E may lead to strokes and prostate cancer.
“We should consider the other mega-dose vitamin studies to be cautionary tales,” Manson said. “It is import that the enthusiasm for vitamin D not outpace the evidence. We don’t want everyone taking 300,000 IUs for preventing menstrual cramps.”