Calcium: could be a secret weapon for females reducing PMS symptoms and more!

One RCT study tested a theory of transient hypocalcemia occurring towards the middle-later portion of the luteal phase in certain women. Subjects who supplemented with 1,000mg calcium for these 7-10 days saw significant reduction in PMS symptoms (Arab et al., 2020). Since divergence from serum calcium homeostasis affects so many systems from cognitive and emotional to muscle contraction and relaxation, I also investigated specific recommendations from this week’s article Recommends 1,000mg/ day of calcium or 1,500mg/ day for amenorrheic athletes. However, one of my questions is if this demand for calcium is increased with athletes who sweat a lot and/ or engage in long duration high-impact sports like distance running or basketball.

One study to support bone health tested ingestion of 1350mg via calcium rich food or supplements 90 minutes before exercise and demonstrated this to help mitigate the volume of bone resorption during exercise since calcium is excreted in sweat (Larrosa et al., 2024). Parathyroid hormone (PTH) levels were lower in calcium-before-exercise group which means less calcium was needed to be extracted from the tissues to get into the blood. Pre-exercise calcium was recommended to be in the form of dairy products, but some may think it would cause GI distress.

However, Haakonssen et al. (2015) did a study on competitive female cyclists and found that if the dairy products were consumed two hours before a 90-minute training session that no adverse gut reactions occurred. Furthermore, their study also showed a reduction in PTH that was 1.55 times lower compared to the group who did not take calcium before the training. Thus, to prevent undue bone resorption in females, timing of calcium intake may be best if supplementing or ingesting calcium rich food (like dairy) 90-120 minutes before strenuous exercise. Back to sweat induced calcium loss, Guillemant et al. (2004) have suggested that males can sweat out 247mg after a single training session of basketball. However, according to Ichinose-Kuwahara et al. (2010), sex differences exist in sweat rates with females having lower volumes of sweating rates and sweating does not increase as significantly as males when exercise intensity increases. 

How can the about research contribute to my clinical practice? First, there is a valid need to communicate and recommend to all female athletes the need to consume adequate calcium. Simple suggestions to my clients might be to eat some Greek yogurt with granola 90 minutes before a training session front-load calcium stores and provide good sources for protein and carbohydrate. Secondly, for females with a cycle I can recommend increasing calcium some during the last 7-10 days of the cycle if they have PMS. Third, for females that engage in endurance training or during the warmer seasons of the year and sweating increases, highlighting the importance of calcium or increasing dosage a few hundred mg may be needed to offset excessive loss in sweat. Research suggests that a bolus of calcium greater than 500mg cannot be fully absorbed and best to spread dosages throughout the day (Holtzman & Ackerman, 2021). Therefore, for my clients I would suggest to dose calcium intake before and after training sessions as wells as several other times throughout the if possible.

References:

Arab, A., Rafie, N., Askari, G., & Taghiabadi, M. (2020). Beneficial Role of Calcium in Premenstrual Syndrome: A Systematic Review of Current Literature. International journal of preventive medicine, 11, 156. https://doi.org/10.4103/ijpvm.IJPVM_243_19

Cuenca, E., López, T., Montoya, J. J., Rodrigues-de-Souza, D. P., Carrillo-Alvarez, E., Casado, A., … Domínguez, R. (2025). Nutritional Strategies for Optimizing Health, Sports Performance, and Recovery for Female Athletes and Other Physically Active Women: A Systematic Review. Nutrition reviews, 83(3), e1068–e1089. https://doi.org/10.1093/nutrit/nuae082

Guillemant, J., Accarie, C., Peres, G., & Guillemant, S. (2004). Acute effects of an oral calcium load on markers of bone metabolism during endurance cycling exercise in male athletes. Calcified tissue international, 74(5), 407–414. https://doi.org/10.1007/s00223-003-0070-0

Holtzman, B., & Ackerman, K. E. (2021). Recommendations and Nutritional Considerations for Female Athletes: Health and Performance. Sports medicine (Auckland, N.Z.), 51(Suppl 1), 43–57. https://doi.org/10.1007/s40279-021-01508-8

Ichinose-Kuwahara, T., Inoue, Y., Iseki, Y., Hara, S., Ogura, Y., & Kondo, N. (2010). Sex differences in the effects of physical training on sweat gland responses during a graded exercise. Experimental physiology, 95(10), 1026–1032. https://doi.org/10.1113/expphysiol.2010.053710

Larrosa, M., Gil-Izquierdo, A., González-Rodríguez, L. G., Alférez, M. J. M., San Juan, A. F., Sánchez-Gómez, Á., Calvo-Ayuso, N., Ramos-Álvarez, J. J., Fernández-Lázaro, D., Lopez-Grueso, R., López-León, I., Moreno-Lara, J., Domínguez-Balmaseda, D., Illescas-Quiroga, R.,