birth control and vitamin d

Women go on —
and go off — birth control for a variety of reasons.

When they
stop taking the medication, however, they may want to check their vitamin D
levels.

Turns out
the amount of vitamin D may drop in a woman’s body when she stops using
hormonal contraceptives that contain estrogen.

This finding was from a study published this
month in the Journal of Clinical Endocrinology & Metabolism
(JCEM)
.

Vitamin D helps manage calcium levels in the blood, which is vital for
bone health.

vitamin d birth control

Pregnant women generate more vitamin D to support formation of the fetal
skeleton, so they face more serious consequences from a vitamin D deficiency.

“Women who were using contraception containing estrogen tended to
have higher vitamin D levels than other women,” Dr. Quaker E. Harmon, Ph.D.,
the lead author of the study with the National Institutes of Health’s (NIH’s)
National Institute of Environmental Health Sciences in Research Triangle Park, North
Carolina, said in a statement. “Our findings suggest that contraceptives
containing estrogen tend to boost vitamin D levels, and those levels are likely
to fall when women cease using contraception,” Harmon added.

She also told Healthline that women going off birth control to conceive
should take steps to make sure they have adequate vitamin D levels.

Harmon added that her team does not know how quickly vitamin D levels
drop after a woman stops taking birth control.

Read more: Children breast-fed after one year may need extra vitamin D »

Easing off estrogen

Dr. Jennifer Wider, a women’s health doctor, and radio show host on
Sirius XM, said the effects of lower amounts of estrogen vary from woman to
woman.

Typical side effects can include minor weight loss (usually water
weight), improved libido, mood swings, deflated breasts, more vaginal
discharge, worsening menstrual cramps, and mittelschmerz (pain during
ovulating).

Women can expect heightened cramping and bleeding upon stopping hormonal
birth control, Dr. Lucky Sekhon, a reproductive
endocrinologist and infertility specialist at Reproductive Medicine Associates of
New York, told Healthline.

What else can happen when you go off hormonal birth control?

Thyroid fluctuations

Women taking thyroid hormone medication may need to lower their dose
upon stopping birth control, Dr. Nanette Santoro, a professor at the University
of Colorado School of Medicine, told Healthline.

Estrogen stimulates a liver protein known as thyroxine binding globulin
(TBG). When it’s high, it gives less to the tissues. Women with normal thyroid
levels produce more thyroxine to get at the right level, and their bodies would
adjust that level down when coming off the pill. But in women taking thyroxine
because their bodies do not make enough, they need a little more to adjust for
the uptick in TBG and then can lower it when coming off the pill because TBG
levels go down.

Blood clots

The patch and the ring cause elevations in liver proteins, raising the
risk for clotting. After about six weeks of stopping hormonal birth control,
that risk is lowered, Santoro noted.

Irregular bleeding

Santoro said many women notice changes in their menstrual flow upon
stopping birth control, and blame the medication. “However … the hormonal
contraception does not cause the problems … [it] simply provides hormones to
the uterus. So if she stops the pill and does not get a monthly period, she
needs a workup to look for all the other causes of irregular periods,” Santoro
said. It can take up to six months to resume ovulation after a woman is on a
long-term oral contraceptive or the Depo-Provera injection, while an IUD is
immediately reversible, Sekhon added.

Fertility

“Pretty much immediately [after stopping hormonal contraception] a
woman’s fertility will return to normal,” Dr. Zaher Merhi, an IVF doctor at the
New Hope Fertility Center in New York, told Healthline.

It doesn’t necessarily take weeks after stopping to become fertile,
added Dr. John Zhang, Ph.D., a fertility specialist in the same practice. “Your
body may be at its most fertile point right after stopping. You can see this by
the numbers of people who forget a pill and become pregnant in that short
window,” he told Healthline.

Less cancer protection

Long-term
oral contraceptive use — at least 10 years — has been shown to reduce a woman’s
lifetime risk of ovarian cancer. “Stopping the birth control pill therefore may
remove that protective benefit,” Sekhon said.

Side effect reversal

Merhi said many women have found that the side effects they experienced
while on birth control reversed when they stopped taking it. “If your skin
cleared up [on contraception], be prepared for an outbreak,” he noted.

Read more: Vaginal ring is the latest tool to prevent HIV in women »