Fertility Diet and Supplements: What the Evidence Actually Shows

The fertility supplement market is a billion-dollar industry built on hope. Walk into any pharmacy or scroll through any fertility forum, and you'll find dozens of products promising to improve egg quality, boost sperm parameters, or enhance IVF success. Some of these claims are supported by genuine clinical evidence. Many are not.

This guide separates the supplements with real research behind them from the ones riding on marketing alone — and tells you when to start, how much to take, and what to realistically expect.

The Evidence Grading System

We're using a simplified evidence framework:

Supplements with the Strongest Evidence

CoQ10 (Coenzyme Q10) — Level 2

CoQ10 is involved in mitochondrial energy production — the process that powers egg maturation and early embryo development. As you age, mitochondrial function declines, which correlates with declining egg quality.

Clinical evidence suggests that CoQ10 supplementation (400–600mg/day of the ubiquinol form) may improve oocyte quality and IVF outcomes, particularly in women over 35 or those with diminished ovarian reserve. Several RCTs have shown improved fertilization rates and embryo quality, though large-scale definitive trials are still ongoing.

When to start: At least 2–3 months before IVF cycle (mitochondrial effects take time). Dosage: 400–600mg/day ubiquinol (the active, better-absorbed form). Cost in Colombia: $15–$30/month.

Vitamin D — Level 2

Vitamin D receptors are present in the ovaries, endometrium, and placenta. Multiple observational studies and several RCTs associate adequate vitamin D levels (>30 ng/mL) with higher IVF success rates, improved implantation, and lower miscarriage rates.

Deficiency is extremely common — estimates suggest 40–60% of reproductive-age women have insufficient vitamin D levels.

When to start: Check your level now; supplement if below 30 ng/mL. Dosage: 1,000–4,000 IU/day depending on baseline level. Cost in Colombia: $5–$10/month.

Folate / Methylfolate — Level 1

Folate's role in preventing neural tube defects is Level 1 evidence — this is one of the most well-established supplements in reproductive medicine. All patients trying to conceive should take 400–800mcg of folate or methylfolate daily.

Methylfolate (5-MTHF) is the active form and is recommended over folic acid for patients with MTHFR gene variants, which affect folate metabolism. Standard prenatal vitamins contain either form.

When to start: At least 1 month before conception; ideally 3 months. Dosage: 400–800mcg/day (higher doses for specific conditions, per your doctor). Cost in Colombia: Included in prenatal vitamins, $5–$15/month.

Omega-3 Fatty Acids (DHA/EPA) — Level 2

Omega-3s reduce inflammation, support hormonal balance, and may improve blood flow to reproductive organs. Studies link higher omega-3 intake with improved IVF outcomes, better embryo morphology, and possibly reduced risk of preterm birth.

When to start: At least 2 months before treatment. Dosage: 1,000–2,000mg combined EPA/DHA daily. Cost in Colombia: $10–$20/month.

Supplements with Moderate Evidence

DHEA — Level 2–3 (Specific Population)

DHEA (dehydroepiandrosterone) is a precursor hormone that the body converts to testosterone and estrogen. For patients with diminished ovarian reserve (DOR) specifically, several studies suggest that DHEA supplementation (75mg/day for 6–12 weeks before IVF) may improve ovarian response, egg yield, and embryo quality.

Important: DHEA should only be used under medical supervision and is specifically indicated for DOR patients. It is not recommended for patients with normal ovarian reserve or PCOS.

Melatonin — Level 2–3

Melatonin acts as an antioxidant in the follicular fluid surrounding developing eggs. Small RCTs suggest that melatonin supplementation (3mg at bedtime) during the stimulation phase may improve oocyte and embryo quality. Evidence is promising but based on small studies.

Inositol (Myo-inositol) — Level 2 for PCOS

For patients with polycystic ovary syndrome (PCOS), myo-inositol (2,000–4,000mg/day) has solid evidence for improving insulin sensitivity, ovulatory function, and oocyte quality. It's not effective or indicated for patients without PCOS.

Supplements with Weak or Insufficient Evidence

The following are commonly marketed for fertility but lack strong clinical evidence. This doesn't mean they're harmful — it means the claims outpace the data:

• Royal jelly — Level 3–4. Animal studies suggest benefit; human data is minimal.
• Maca root — Level 3–4. May support libido; no direct evidence for IVF outcomes.
• Vitex (chasteberry) — Level 3. Some evidence for menstrual regularity; not studied in IVF specifically.
• Fertility "blends" — Level 4. Proprietary combinations with inadequate dosing of individual ingredients and no clinical testing of the specific formulation.

The Mediterranean Diet Connection

The strongest dietary evidence for fertility isn't about individual nutrients — it's about overall eating patterns. Multiple studies, including a landmark Dutch study of over 200 IVF patients, found that adherence to a Mediterranean-style diet was associated with a 40% higher probability of pregnancy following IVF.

The Mediterranean diet emphasizes:

• Vegetables, fruits, and legumes as dietary foundations
• Whole grains over refined carbohydrates
• Olive oil as the primary fat source
• Fish 2–3 times per week (omega-3 source)
• Limited red meat and processed foods
• Minimal added sugars

For patients spending 2–3 weeks in Colombia for IVF, the local food culture aligns naturally with many of these principles — abundant fresh fruit, fish, and vegetables are dietary staples.

For Male Partners: Sperm Quality Supplements

Male factor contributes to approximately 40–50% of infertility cases. Supplements with evidence for improving sperm parameters:

• CoQ10 (200–400mg/day) — Level 2 for motility improvement
• Zinc (30mg/day) — Level 2 for sperm count and testosterone
• Selenium (200mcg/day) — Level 2–3 for motility
• L-carnitine (2,000mg/day) — Level 2 for motility and morphology
• Vitamin C (500–1,000mg/day) — Level 2 for DNA fragmentation reduction
• Vitamin E (400 IU/day) — Level 2–3 for oxidative protection

The male partner should start supplementation at least 3 months before IVF — that's the length of a full spermatogenesis cycle, meaning current supplements affect sperm that will be produced 90 days from now.

A Realistic Framework