Calcium for fertility

On this page

1. What is calcium?
2. Function and how it works
3. Fertility benefits
4. Recommended daily dose
5. Food sources
6. Cautions and contraindications
7. My Fertility Guide
8. Related pages

1. What is calcium?

Calcium is the most abundant mineral in the body. Around 99% is stored in bones and teeth, with the remaining 1% playing critical roles in muscle contraction, nerve signalling, blood clotting, hormone secretion and — importantly for fertility — egg activation at the moment of fertilisation. Calcium absorption depends on adequate vitamin D levels.

Reference ranges and recommended intakes vary from country to country — always interpret guidance against the recommendations of your own healthcare authority.

2. Function and how it works

Calcium has several roles in fertility:

1. Egg activation. When a sperm enters the egg, a calcium wave passes across the egg, triggering the metabolic activation that initiates embryonic development. Without adequate calcium, egg activation can fail.
2. Sperm function. Calcium is required for sperm hyperactivation and the acrosome reaction that allows the sperm to penetrate the egg.
3. Bone reservoir. Adequate maternal calcium reserves protect bone health during pregnancy, when the baby draws calcium from the mother for skeletal development.
4. Hormone secretion. Calcium signalling is involved in the release of multiple hormones throughout the body.

3. Fertility benefits

Adequate calcium intake supports the moment of fertilisation, healthy hormone signalling and the bone reserves needed for pregnancy. Caffeine and excessive consumption of vitamin C-rich citrus or coffee can reduce calcium absorption — another reason to moderate caffeine when trying to conceive.

4. Recommended daily dose

I recommend a daily dose of 1,000 mg of calcium for women of reproductive age, ideally split into two doses with meals for better absorption. The daily total should include calcium from both food and supplements. Always pair calcium with adequate vitamin D.

5. Food sources

Although dairy products are widely promoted as the best calcium source, broccoli, almonds and tinned salmon contain more absorbable calcium than milk. I recommend NOT sourcing calcium primarily from dairy as cow's milk is heavy on the digestive system and can weaken it (in TCM terms, generating dampness). Better calcium sources include:

1. Broccoli, kale and other dark leafy greens (more absorbable than milk)
2. Almonds, Brazil nuts and hazelnuts
3. Tinned salmon and sardines (with bones)
4. Sesame seeds and tahini
5. Quinoa
6. Kelp and nori seaweed
7. Parsley
8. Sunflower seeds
9. Eggs

6. Cautions and contraindications

1. Caffeine reduces calcium absorption — limit coffee, especially around supplement-taking times.
2. Calcium can affect the absorption of iron and thyroid medications — take these supplements at different times of day.
3. Excess calcium without adequate vitamin K2 can contribute to calcification of soft tissues.
4. Always consult with a fertility specialist or your doctor before starting any new supplement regime.

7. My Fertility Guide

8. Related pages

• Fertility supplements directory
• Vitamin D — required for calcium absorption
• Vitamin K — directs calcium into bones
• Magnesium
• Iron
• Oestrogen