Calcium

Supplement 2: Calcium

What is it?

Calcium: Minerals are defined as chemical elements required as essential nutrients to maintain body functions¹.

Calcium can be found in a variety of foods, including:

• Dairy products, such as cheese, milk and yogurt

• Dark green leafy vegetables, such as broccoli and kale

• Fish with edible soft bones, such as sardines and canned salmon

• Calcium-fortified foods and beverages, such as soy products, cereal and fruit juices, and milk substitutes².

How does it work?

Calcium decreases with rising estrogen concentrations which leads to decrease in neurotransmitter synthesis and release, leading to decrease in serotonin levels, causing mood changes during PMS. The calcium effect on PMS is correlated to the production of serotonin and tryptophan metabolism.⁴

Calcium supplementation may act by resolving an underlying physiologic deficit, suppressing parathyroid hormone secretion, and, ultimately, reducing neuromuscular irritability and vascular reactivity. .

Recommended dose: ACOG recommends supplementation of 1.2 mg calcium daily to alleviate both physical and psychological PMS symptoms, especially reducing water retention and breast tenderness³.

What is the efficacy?

Methods: All three studies used randomized, double-blind designs to evaluate the effect of calcium supplementation on PMS symptoms. Sample sizes ranged from 39 to 466 women, with calcium doses between 500 mg and 1,200 mg per day, administered over 2 to 4 menstrual cycles. Interventions were compared against placebo, and in one study, also against fluoxetine.^4,5,6

Results: Across all three studies, calcium supplementation significantly reduced PMS symptoms. There was a ~48% reduction in symptom severity by the third cycle in the calcium group, compared to ~30% in the placebo group. Significant improvements were noted in emotional and somatic symptoms over two cycles with 500 mg/day calcium (p ≤ 0.01). In the another study, calcium showed modest symptom improvement (effect sizes 0.10–0.44), though less effective than fluoxetine. Overall, calcium was consistently more effective than placebo.

Conclusion: Calcium supplementation—typically 500–1,200 mg daily—appears to be a well-tolerated, low‑risk, and effective option for reducing PMS symptoms, particularly mood-related issues like anxiety, depression, and emotional instability.

Side effects:

Short-term effects: Constipation, diarrhea, abdominal pain

Long-term effects: Kidney stones, Cardiovascular problems, colorectal neoplasms.⁷

References

1. Kaewrudee S, Kietpeerakool C, Pattanittum P, Lumbiganon P. Vitamin or mineral supplements for premenstrual syndrome. Cochrane Database Syst Rev. 2018 Jan 18;2018(1):CD012933. doi: 10.1002/14651858.CD012933.

2. National Institutes of Health, Office of Dietary Supplements. Calcium and Vitamin D: Important for Bone Health [Internet]. Bethesda (MD): National Institutes of Health; [cited 2025 Apr 23]. Available from: https://www.niams.nih.gov/health-topics/calcium-and-vitamin-d-important-bone-health

3. Oboza P, Ogarek N, Wójtowicz M, Rhaiem TB, Olszanecka-Glinianowicz M, Kocełak P. Relationships between premenstrual syndrome (PMS) and diet composition, dietary patterns and eating behaviors. Nutrients. 2024 Jun 17;16(12):1911. doi: 10.3390/nu16121911.

4. Shobeiri F, Ezzati Araste F, Ebrahimi R, Jenabi E, Nazari M. Effect of calcium on premenstrual syndrome: A double-blind randomized clinical trial. Obstet Gynecol Sci. 2017 Jan 15;60(1):100–5. doi: 10.5468/ogs.2017.60.1.100.

5. Thys-Jacobs S, Starkey P, Bernstein D, Tian J, Premenstrual Syndrome Study Group. Calcium carbonate and the premenstrual syndrome: effects on premenstrual and menstrual symptoms. American journal of obstetrics and gynecology. 1998 Aug 1;179(2):444-52.

6. Yonkers KA, Pearlstein TB, Gotman N. A pilot study to compare fluoxetine, calcium, and placebo in the treatment of premenstrual syndrome. Journal of clinical psychopharmacology. 2013 Oct 1;33(5):614-20.

1. Li K, Wang X-F, Li D-Y, Chen Y-C, Zhao L-J, Liu X-G, Guo Y-F, Shen J, Lin X, Deng J, Zhou R. The good, the bad, and the ugly of calcium supplementation: a review of calcium intake on human health. Clin Interv Aging. 2018 Nov 28;13:2443–52. doi: 10.2147/CIA.S157523.