Fertility is complex and is affected by a number of factors, one of these is the abundance of or deficiency of certain nutrients in the diet. Vitamin B12 is one such vitamin and is also crucial to a healthy pregnancy.1
With regards to maternal health, clinical studies have shown that vitamin B12 suffiency may be a factor in fertility or recurrent spontaneous abortion. Starting pregnancy with an adequate vitamin B12 status may reduce the risk of birth defects such as neural tube defects (NTDs), and may decrease the incidence of preterm delivery, although this needs further evaluation.1 One study found that women with adequate B12 levels were less likely to give birth to a child with birth defects.2 In another study, the obstetric histories of patients presenting with episodes of vitamin B12 deficiency were analysed. Infertility (two to eight years) had been present in some episodes, while recurrent foetal loss was a feature in others. In some, periods of recurrent foetal loss were followed by periods of infertility greater than one year. The study concluded that hypercoagulability due to raised homocysteine levels may lead to foetal loss when vitamin B12 deficiency first develops. A more prolonged deficiency results in infertility by causing changes in ovulation or development of the ovum or changes leading to defective implantation.3 Furthermore, inadequate vitamin B12 status in the mother may lead to frank deficiency in the infant if sufficient foetal stores of vitamin B12 are not laid down during pregnancy or are not available in breastmilk. However, the implications of this also need more research.1
CoQ10 is known for its role in cellular energy as well as its antioxidant activity. However we can also see a link between CoQ10 and both male and female fertility. Ubiquinol is the fully reduced form of coenzyme Q10 (CoQ10H2).4,5 It has been established that Individuals who require coenzyme Q10 supplementation can benefit from using the ubiquinol form. This is due to several factors, including the higher concentrations of ubiquinol compared with ubiquinone in energy-producing mitochondria and mitochondrial-rich tissues, the physiological requirement for the body to convert to the ubiquinol form following ingestion for biological effect, and the superior bioavailability of the ubiquinol form when taken in supplemental form.4,6
In one prospective, randomized controlled study, 186 consecutive female patients with poor ovarian reserve parameters (POR) stratified according to the POSEIDON classification group 3 (age < 35)) were studied. The participants were randomized to the CoQ10 pre-treatment of 200 mg 3x per day, for 60 days preceding IVF-ICSI cycle or no pre-treatment. The number of high-quality embryos was a primary outcome measure. Women in the CoQ10 group had increased numbers of retrieved oocytes, higher fertilization rates and more high-quality embryos. Significantly less women treated with CoQ10 had cancelled embryo transfer because of poor embryo development than controls and more women from the treatment group had available cryopreserved embryos. The clinical pregnancy and live birth rates per embryo transfer and per one complete stimulation cycle tended to be higher in the CoQ10 group but did not achieve statistical significance. Pre-treatment with CoQ10 appears to improve ovarian response to stimulation and embryological parameters in young women with poor ovarian reserve in IVF-ICSI cycles. Further work is required to determine whether there is an effect on clinical treatment endpoints.7
It has been shown that CoQ10 supports mitochondrial energy production, which influences sperm motility and its antioxidant mechanisms help maintain sperm health.8-10 Male infertility has been associated with oxidative stress and the level of CoQ10 in seminal fluid is considered to be an important biomarker of sperm health.8 In addition various clinical trials report that CoQ10 supplements, taken at a dose of 200mg -300mg per day has resulted in significant increases in sperm motility, sperm count and improved sperm health.10-12 Given the evidence it is reasonable to conclude that both vitamin B12 and ubiquinol may assist in supporting fertility in the circumstances outlined above.