Vitamin D deficiency threatens fertility and women’s health, warns Lahore gynaecologist

_*Low levels of the sunshine vitamin may increase the risk of menstrual disorders, PCOS, infertility, pregnancy complications and bone weakness, while maintaining adequate levels can support women’s reproductive health from adolescence to menopause, says Dr Andleeb Arshad*_

Vitamin D deficiency is emerging as an important health concern for women as it can affect their reproductive health, fertility and overall well-being at different stages of life, from adolescence and pregnancy to menopause.

Medical experts have warned that low levels of vitamin D may be associated with menstrual irregularities, painful periods, polycystic ovary syndrome (PCOS), unexplained infertility and reduced ovarian reserve. Its deficiency may also increase the risk of complications during pregnancy and accelerate bone loss after menopause.

Dr Andleeb Arshad, Assistant Professor at Ameer-ud-Din Medical College and a gynaecologist at Lahore General Hospital, said this while speaking at a Vitamin D-related seminar in Lahore. She spoke on how vitamin D supports women’s reproductive health and why its adequate levels are important throughout life.

She said more than one billion people worldwide were affected by vitamin D deficiency, while an estimated 70 to 80 percent of Pakistan’s population had low levels of the vitamin. She added that the problem was more common among women than men, particularly in South Asia.

Describing vitamin D as the sunshine vitamin, Dr Arshad said it was important for everyone, but its role in women’s health deserved particular attention.

“Vitamin D is not simply a nutrient but also acts as a hormone in the body. Its receptors are present in several parts of the female reproductive system, including the brain, ovaries, uterus, placenta and breast tissues,” she said. “This shows that vitamin D is involved in several processes linked to reproductive and hormonal health.”

According to her, women’s health should be protected from an early age because the physical development and bone strength built during adolescence can influence their health in later years.

Menstrual problems and adolescence

Discussing the health problems faced by adolescent girls, Dr Arshad said irregular periods and painful menstruation were among the common complaints brought to gynaecologists.

She said research had linked very low vitamin D levels, particularly below 12 nanograms per millilitre, with a higher risk of severe menstrual pain among adolescent girls.

She said that vitamin D helped control certain chemical processes in the body that were involved in the production of prostaglandins. These substances contribute to uterine contractions during menstruation and can cause pain when produced in excessive amounts.

According to her, low vitamin D levels may increase this problem and contribute to severe menstrual discomfort.

Vitamin D and polycystic ovary syndrome

Dr Arshad identified polycystic ovary syndrome as another important concern among women of reproductive age.

She said studies suggested that around 67 to 85 percent of women with PCOS also suffered from vitamin D deficiency, with their levels often falling below 20 nanograms per millilitre.

PCOS is a hormonal condition that can cause irregular periods, increased levels of male hormones, insulin resistance and problems with ovulation.

Explaining the connection, she said vitamin D receptors were present in the insulin-producing cells of the pancreas. A deficiency could affect insulin production and the body’s response to insulin, potentially making insulin resistance worse.

She added that low vitamin D levels could also be associated with increased free androgen levels and reduced levels of sex hormone-binding globulin, a protein that helps regulate sex hormones.

These changes could contribute to irregular menstruation and problems with the normal development of ovarian follicles, affecting the release of eggs.

Importance for fertility and IVF treatment

Highlighting the connection between vitamin D and fertility, Dr Arshad said its deficiency had also been associated with unexplained infertility and a reduced ovarian reserve.

She explained that ovarian reserve refers to the remaining supply of eggs in a woman’s ovaries and is an important factor in assessing reproductive potential.

She said anti-Müllerian hormone (AMH) was an important indicator of ovarian reserve. It was produced by granulosa cells in developing ovarian follicles.

According to her, vitamin D helped regulate AMH production and supported the development of ovarian follicles. It also played a role in the production of reproductive hormones and the response of ovarian follicles to follicle-stimulating hormone (FSH).

She said these functions made vitamin D important for women facing fertility problems.

Discussing in-vitro fertilisation (IVF), a treatment in which eggs and sperm are brought together to help achieve pregnancy, she said maintaining adequate vitamin D levels could be important for women undergoing the procedure, particularly those with PCOS.

Referring to a 2025 systematic review, she said the vitamin D level before treatment might influence IVF success in women with PCOS, although the available research had not produced consistent results.

She also referred to a study involving 59 women undergoing IVF, which highlighted the importance of normal vitamin D levels among patients with PCOS.

Dr Arshad said some experts recommended maintaining vitamin D levels above 30 nanograms per millilitre before IVF treatment. However, she stressed that larger studies were still needed to establish the benefits more clearly.

She added that vitamin D supplementation could also help improve blood lipid levels among women with PCOS.

Risks during pregnancy and breastfeeding

Speaking about pregnancy and breastfeeding, Dr Arshad said vitamin D was important for both the mother and the developing baby.

She explained that women with vitamin D deficiency could face a higher risk of pregnancy-related complications, including pregnancy-induced high blood pressure, gestational diabetes and premature labour.

She said vitamin D helped regulate the renin-angiotensin system, which plays a role in controlling blood pressure. It also supported the development of blood vessels in the placenta and helped control inflammation.

According to her, these functions were important for a healthy pregnancy, and low vitamin D levels could be associated with an increased risk of pre-eclampsia, a serious condition involving high blood pressure during pregnancy.

She further explained that vitamin D played a role in controlling blood sugar levels because its receptors were also present in the insulin-producing cells of the pancreas.

Endometriosis, fibroids and pelvic pain

Dr Arshad said women of reproductive age could also face problems such as uterine fibroids, heavy menstrual bleeding, pelvic pain, endometriosis and recurring vaginal infections.

Explaining the role of vitamin D in endometriosis, she said its active form helped control inflammation by reducing the activity of certain inflammatory substances in endometrial tissue.

Endometriosis is a condition in which tissue similar to the lining of the uterus grows outside the uterus, often causing severe pain and sometimes fertility problems.

She added that vitamin D could also help control the growth of cells and the production of substances involved in tissue formation. These effects might be relevant to uterine fibroids, which are non-cancerous growths in the uterus.

According to her, vitamin D could help limit the growth of certain cells and reduce the production of the material that supports the development of fibroids.

Menopause and bone health

Discussing women’s health after menopause, Dr Arshad said declining oestrogen levels increased the risk of bone loss and muscle weakness.

She explained that oestrogen helped maintain bone strength by supporting the body’s ability to absorb and use calcium. When oestrogen levels declined after menopause, women became more vulnerable to bone loss.

If vitamin D levels were also low, the problem could become more serious because vitamin D was essential for calcium absorption and bone health.

She said the combination of reduced oestrogen and vitamin D deficiency could accelerate bone loss, increasing the risk of osteopenia and osteoporosis.

Osteopenia refers to lower-than-normal bone density, while osteoporosis is a condition in which bones become weak and fragile, making fractures more likely.

She added that postmenopausal vitamin D deficiency had also been associated with muscle weakness, increased arterial stiffness, abnormal blood lipid levels and more severe symptoms such as hot flashes.

Concluding her presentation, Dr Arshad advised women to maintain a healthy diet containing calcium and vitamin D, get sensible exposure to sunlight and exercise regularly.

She also recommended checking vitamin D levels when medically required and taking supplements according to a doctor’s advice.

She stressed that attention to vitamin D levels at different stages of life could help women protect their reproductive health, fertility, bone strength and overall well-being.