The importance of the one carbon cycle nutritional support in human male fertility: a preliminary clinical report

Reprod Biol Endocrinol. 2014 Jul 29;12:71. doi: 10.1186/1477-7827-12-71.


Background: Sperm chromatin structure is often impaired; mainly due to oxidative damage. Antioxidant treatments do not consistently produce fertility improvements and, when given at high doses, they might block essential oxidative processes such as chromatin compaction. This study was intended to assess the effect on male sub-fertility of a pure one carbon cycle nutritional support without strong antioxidants.

Methods: Male partners of couples resistant to at least 2 assisted reproductive technology (ART) attempts, with no evidence of organic causes of infertility and with either DNA fragmentation index (DFI) measured by Terminal deoxynucleotidyl transferase dUTP Nick End Labeling (TUNEL) or nuclear decondensation index (SDI) measured by aniline blue staining exceeding 20%, were invited to take part in a trial of a nutritional support in preparation for a further ART attempt. The treatment consisted of a combination of B vitamins, zinc, a proprietary opuntia fig extract and small amounts of N-acetyl-cysteine and Vitamin E (Condensyl™), all effectors of the one carbon cycle.

Results: 84 patients were enrolled, they took 1 or 2 Condensyl™ tablets per day for 2 to 12 months. Positive response rates were 64.3% for SDI, 71.4% for DFI and 47.6% for both SDI and DFI. Eighteen couples (21%) experienced a spontaneous pregnancy before the planned ART cycle, all ended with a live birth. The remaining 66 couples underwent a new ART attempt (4 IUI; 18 IVF; 44 ICSI) resulting in 22 further clinical pregnancies and 15 live births. The clinical pregnancy rate (CPR) and the live birth rate (LBR) were 47.6% and 39.3% respectively. The full responders, i.e. the 40 patients achieving an improvement of both SDI and DFI, reported a CPR of 70% and a LBR of 57.5% (p<0.001).

Conclusions: Nutritional support of the one carbon cycle without strong antioxidants improves both the SDI and the DFI in ART resistant male partners and results in high pregnancy rates suggesting a positive effect on their fertility potential.

Publication types

  • Clinical Trial
  • Comparative Study

MeSH terms

  • Acetylcysteine / administration & dosage
  • Acetylcysteine / therapeutic use
  • Adult
  • Birth Rate
  • Dietary Supplements*
  • Embryo Implantation
  • Family Characteristics
  • Female
  • Fertilization in Vitro
  • Fruit / chemistry
  • Homocysteine / metabolism*
  • Humans
  • Infertility, Male / diet therapy*
  • Infertility, Male / metabolism
  • Insemination, Artificial, Homologous
  • Male
  • Middle Aged
  • Opuntia / chemistry
  • Plant Extracts / administration & dosage
  • Plant Extracts / therapeutic use
  • Pregnancy
  • Pregnancy Rate
  • Switzerland / epidemiology
  • Vitamin B Complex / administration & dosage
  • Vitamin B Complex / therapeutic use
  • Vitamin E / administration & dosage
  • Vitamin E / therapeutic use
  • Zinc / administration & dosage
  • Zinc / therapeutic use


  • Plant Extracts
  • Homocysteine
  • Vitamin B Complex
  • Vitamin E
  • Zinc
  • Acetylcysteine