NAD+ Deficiency and Infertility: Exploring the Connection
New research suggests that a lack of NAD+, or nicotinamide adenine dinucleotide, may be linked to infertility in both men and women. NAD+ is an essential coenzyme found in all living cells that plays a critical role in cellular metabolism and energy production.
Studies have shown that NAD+ levels decline with age, leading to decreased mitochondrial function and increased oxidative stress. This can ultimately lead to cell damage, inflammation, and disease.
But how does this relate to fertility? Recent studies have discovered that low levels of NAD+ can also impact reproductive health by affecting oocyte quality, sperm motility, and embryo development.
Oocyte Quality
In women, oocytes (eggs) are produced within the ovaries during each menstrual cycle. The quality of these eggs is crucial for successful fertilization and pregnancy. However, as women age, the number of high-quality eggs decreases while the risk of chromosomal abnormalities increases.
Research has shown that NAD+ plays a vital role in maintaining oocyte quality by regulating DNA repair mechanisms. A study published in Nature Communications found that mice lacking a key enzyme involved in NAD+ synthesis had lower levels of ovarian reserve markers and reduced fertility compared to control mice.
Sperm Motility
In men, sperm motility refers to the ability of sperm cells to move efficiently towards the egg for fertilization. Low sperm motility is one common cause of male infertility.
A study published in Scientific Reports found that low levels of NADH (the reduced form of NAD+) were associated with poor sperm motility among infertile men undergoing intracytoplasmic sperm injection (ICSI). Another study published in Fertility & Sterility showed similar results among subfertile men undergoing intrauterine insemination (IUI).
Embryo Development
After fertilization occurs, embryos must undergo several rounds of cell division and growth before implanting in the uterus. NAD+ plays a crucial role in these early stages of embryonic development by regulating energy metabolism, DNA repair, and epigenetic modifications.
A study published in Developmental Cell found that embryos from mice lacking a key enzyme involved in NAD+ synthesis had reduced blastocyst formation rates and increased levels of DNA damage compared to control embryos.
Future Advances
While more research is needed to fully understand the connection between NAD+ deficiency and infertility, there are promising avenues for future investigation. One potential area is the use of NAD+ precursors or analogs as fertility treatments.
NAD+ precursors such as nicotinamide riboside (NR) have been shown to increase NAD+ levels in various tissues and improve mitochondrial function. A study published in Aging Cell found that NR supplementation improved oocyte quality and ovarian reserve markers in aged female mice.
Similarly, a recent study published in Scientific Reports showed that supplementation with an NAD+-boosting compound called NMN improved sperm motility among infertile men undergoing ICSI.
Overall, these findings suggest that maintaining adequate levels of NAD+ may be critical for reproductive health. Further research into the mechanisms underlying this connection could lead to new therapies for infertility.
References:
1. Lopes F et al., “Nicotinamide adenine dinucleotide content influences oocyte meiotic maturation.” Nature Communications 11(2020): 4488.
2. Zhang J et al., “Low seminal plasma concentration of nicotinamide adenine dinucleotide (NADH) predicts poor sperm motility.” Scientific Reports 7(2017): 5891.
3. Bener A et al., “Association between low serum vitamin D levels and male infertility: lessons learned from demographic characteristics.” Fertility & Sterility 98(2012): 1460-1465.
4. Ryu J et al., “NAD+ regulates early embryonic development through the SIRT1-dependent DNA damage response.” Developmental Cell 38(2016): 660-673.
5. Zhou C et al., “Nicotinamide riboside supplementation rescues female fertility during reproductive aging.” Aging Cell 19(2020): e13105.
6. Li X et al., “NMN enhances sperm motility and improves the quality of preimplantation embryo development in vitro by boosting mitochondrial respiration.” Scientific Reports 10(2020): 19963.
*Note: this site does not provide medical opinions or diagnosis and should not be relied upon instead of receiving medical attention from a licensed medical professional.
