No published clinical studies in humans have evaluated the safety of NAD+ or its precursors, including NR, NMN, or high doses of niacin or nicotinamide, during pregnancy or breastfeeding.
Due to the lack of such safety data—and not because there is specific evidence indicating that these compounds are harmful—the most appropriate conclusion is that NAD+ supplementation should not be started or continued during pregnancy or breastfeeding without prior consultation with an obstetrician, midwife, or other qualified healthcare professional.
In this article, we explain what is currently known, what remains unknown, and why medical consultation is particularly important in this situation.
What is actually known about the safety of NAD+ in pregnancy?
The most important starting point is that no randomized, placebo-controlled human study has evaluated the safety of NR, NMN, or any other NAD+ precursor supplement during pregnancy.
The most important human studies discussed in our other guides on NAD+ were conducted in non-pregnant adults. Pregnancy is routinely used as an exclusion criterion in this type of clinical research.
However, another issue was investigated: what happens when proper NAD+ biosynthesis is disrupted during pregnancy.
One important study identified genetic mutations that disrupt the natural pathway for NAD+ production from tryptophan, known as the de novo synthesis pathway. In affected families, these disorders were associated with numerous birth defects, including those affecting the heart, spine, and kidneys [1].
The same study also used a mouse model with a similar NAD+ biosynthesis disorder. In this model, supplementation with niacin, a dietary precursor of NAD+ and a form of vitamin B3, prevented birth defects associated with the deficiency state [1].
Related animal studies have also shown that NAD+ deficiency resulting from a combination of genetic and environmental factors may contribute to birth defects and pregnancy loss in mice [2].
These results are significant, but require careful interpretation.
They show that proper NAD+ metabolism is important during pregnancy and fetal development. They also support the importance of an adequate supply of vitamin B3 as part of proper nutrition.
However, they do not prove that concentrated or high-dose NAD+ precursor supplements are safe during human pregnancy.
Correcting a nutritional or metabolic deficiency is not the same as supplementing beyond normal physiological requirements.
The question „is adequate vitamin B3 intake important during pregnancy?” is therefore completely different from the question „have high doses of NAD+ precursors been studied and found to be safe during human pregnancy?”.
The first of these statements is supported by nutritional and developmental biology data. The second has not been established.
For this reason, results from animal studies showing that niacin can correct a specific NAD+ deficiency state should not be interpreted as proof that high doses of NR, NMN, or other NAD+-related products are safe during pregnancy.
Why does a research gap exist?
The lack of NAD+ studies conducted specifically in pregnant women is not unusual.
Pregnant individuals are often excluded from early-phase clinical trials of new drugs, supplements, or other biologically active compounds.
This is primarily due to ethical and regulatory reasons.
An insufficiently studied intervention could potentially affect fetal development, which is why researchers typically avoid deliberately exposing pregnant individuals to compounds that do not yet have an adequately established safety history.
Even after extensive study of a given compound in non-pregnant adults, research conducted specifically during pregnancy requires additional ethical evaluation, careful monitoring, and appropriately designed protocols.
Research on NAD+ precursors is still a relatively young field.
Most human studies on compounds such as NR and NMN have been published in the last few years, with a significant portion of them focusing on short-term safety, biomarkers, metabolism, aging-related biology, and specific populations with diseases.
The evidence base is therefore not yet at a stage of development where dedicated safety studies in pregnancy can typically be expected.
Therefore, the current lack of data regarding pregnancy should not automatically be interpreted as evidence of harm.
However, it should not be treated as proof of safety either.
The most appropriate conclusion is simply that the safety of using concentrated NAD+ precursors during human pregnancy remains unknown.
Breastfeeding issues
The evidentiary gap regarding breastfeeding is similarly large.
No published human study has determined whether NR, NMN, NAD+, or their major metabolites pass into human breast milk.
There is also no reliable human data showing what concentrations might appear in milk following supplementation or what exposure a breastfed infant might experience.
Without these data, the child's exposure cannot be accurately estimated.
This is important because an infant's body weight is significantly lower than that of an adult, and their metabolism, renal function, liver function, and stage of development are also different.
Therefore, it cannot be assumed that a dose or exposure well tolerated by adults will have the same safety profile in an infant.
It is also unknown whether metabolites resulting from supplementation with NR, NMN, or other NAD+-related compounds could have a clinically significant effect on a breastfed infant.
Absence of evidence does not mean evidence of harm.
It means that the relevant safety issues have not been sufficiently investigated.
For this reason, breastfeeding should also be regarded as a situation where general safety data from studies in adults cannot be directly applied.
Why is „consult a doctor” actually the right answer here?
In this context, the recommendation to consult a healthcare professional is not merely a standard disclaimer.
It reflects the main limitation of the available evidence.
At the same time, two important facts exist.
First of all, NAD+ metabolism is biologically important during pregnancy and fetal development. Studies on genetic and metabolic NAD+ deficiencies have shown that disruption of this pathway can have serious developmental consequences [1,2].
Secondly, there are no clinical human safety data to determine the effect of concentrated NAD+ precursor supplementation during pregnancy or breastfeeding.
This combination makes an individual medical assessment particularly important.
The fact that a given biological pathway is important does not automatically mean that further modifying it is safe.
The lack of safety data during pregnancy also means that results obtained in healthy, non-pregnant adults cannot be reliably used to answer questions regarding fetal development or infant exposure during breastfeeding.
A healthcare professional who knows the course of the pregnancy, diet, medical history, medications used, laboratory test results, and individual risk factors can better assess whether additional supplementation is appropriate.
This is of particular importance because nutritional requirements during pregnancy differ from the needs of the general adult population, and standard prenatal care already includes specific recommendations for vitamins and minerals.
If someone is pregnant, planning a pregnancy, or breastfeeding and is considering taking an NAD+ precursor supplement, the proper next step is to discuss this with an obstetrician, midwife, pharmacist, or other qualified prenatal care professional before starting or continuing use of the product.
General safety data for NR, NMN, or NAD+ in adults should not be considered a substitute for individual medical advice regarding pregnancy.
Limitations of current evidence
- No published human clinical trials have evaluated the safety of NR, NMN, NAD+, or high-dose niacin or nicotinamide supplementation specifically during pregnancy.
- No published human clinical study has confirmed the safety of these compounds during breastfeeding.
- Most available human studies on NAD+ precursors exclude pregnant women, therefore general safety results in adults cannot be considered applicable to pregnancy.
- Studies linking NAD+ deficiency to congenital defects concern genetic or environmental deficiency states, rather than the safety of supplementation exceeding normal physiological requirements [1,2].
- Animal study results showing that niacin can correct developmental disorders associated with NAD+ deficiency in specific models do not prove that high-dose supplementation with NAD+ precursors is safe during a normal human pregnancy.
- There is a lack of reliable human data determining whether NR, NMN, NAD+, or their essential metabolites pass into human breast milk.
- There is a lack of reliable data determining the degree of infant exposure during breastfeeding following maternal supplementation with NAD+ precursors.
- The impact of long-term maternal supplementation on fetal development, the course of pregnancy, infant development, and the safety of breastfeeding remains unknown.
- The lack of documented harm should not be interpreted as proof of safety when appropriate clinical studies in pregnancy have not been conducted.
Disclaimer
The article is for educational purposes only and summarizes scientific research. It does not constitute medical, obstetrical, pediatric, or breastfeeding advice.
Current evidence does not allow to determine whether NAD+, NR, NMN, or high-dose niacin or nicotinamide supplements are safe or unsafe during pregnancy or breastfeeding. Above all, it reflects a lack of adequate human safety studies in these populations.
NAD+ and its precursors should not be presented as FDA- or EMA-approved treatments for issues related to pregnancy, fetal development, breastfeeding, or for other medical purposes, unless referring to a specific approved medicinal product and indication.
Adequate supply of vitamin B3 is a recognized component of proper nutrition, including during pregnancy, but proper dietary requirements should not be equated with the use of concentrated or high-dose supplements of NAD+ precursors.
Do not start, continue, significantly increase, or discontinue the supplement during pregnancy or breastfeeding without prior consultation with an obstetrician, midwife, pharmacist, or other appropriately qualified healthcare professional.
Questions regarding individual vitamin B3 requirements, prenatal supplements, nutritional deficiencies, or NAD+-related products during pregnancy or breastfeeding should be discussed with the healthcare professional responsible for your prenatal or postpartum care.
References
[1] Shi, H., Enriquez, A., Rapadas, M., Martin, E. M. M. A., Wang, R., Moreau, J., Lim, C. K., Szot, J. O., Ip, E., Hughes, J. N., Sugimoto, K., Humphreys, D. T., McInerney-Leo, A. M., Leo, P. J., Maghzal, G. J., Halliday, J., Smith, J., Colley, A., Mark, P. R., Collins, F., Sillence, D. O., Winlaw, D. S., Ho, J. W. K., Guillemin, G. J., Brown, M. A., Kikuchi, K., Thomas, P. Q., Stocker, R., Giannoulatou, E., Chapman, G., Duncan, E. L., Sparrow, D. B., & Dunwoodie, S. L. (2017). NAD deficiency, congenital malformations, and niacin supplementation. New England Journal of Medicine, 377(6), 544–552. https://doi.org/10.1056/NEJMoa1616361
[2] Cuny, H., Rapadas, M., Gereis, J., Martin, E. M. M. A., Kirk, R. B., Shi, H., & Dunwoodie, S. L. (2020). NAD deficiency due to environmental factors or gene-environment interactions causes congenital malformations and miscarriage in mice. Proceedings of the National Academy of Sciences, 117(7), 3738–3747. https://doi.org/10.1073/pnas.1916588117