Unlocking Fertility: The Critical Role of B Vitamins for Men and Women

According to the World Health Organization, 1 in 6 people worldwide will experience infertility at some stage in their lives.¹ As more individuals seek out natural ways to improve their chances of conception, good nutrition is proving to be a powerful asset for supporting reproductive health.

Why Nutrition Matters For Fertility

While assisted reproductive technologies offer valuable support for couples struggling to conceive, research increasingly highlights the important role that nutrition and lifestyle changes can play in enhancing fertility. Following a balanced, nutrient-rich diet in the months leading up to conception can help support overall health, but certain vitamins and food groups may have a more direct influence on reproductive function. Among the most important—yet often overlooked—are the B vitamins, some of which help regulate hormones, support cell division, and contribute to the development of maternal tissues during early pregnancy.

Understanding Your Fertility Landscape

Even though age is the strongest factor affecting female fertility, other areas of reproductive health can still be optimised to support better outcomes.

Body Weight & Nutrition:

Research shows that women with obesity may face greater challenges when it comes to fertility treatments, pregnancy, and birth outcomes.² The good news is that adopting a Mediterranean-style diet has been linked to improved reproductive health and higher pregnancy rates in women. It’s also been found to benefit men by supporting better sperm quality.³ More broadly, cutting back on processed foods, sugary drinks, and unhealthy fats helps to improve fertility outcomes—particularly for those undergoing assisted reproductive treatments.⁴

Lifestyle Choices:

The following lifestyle factors can impact reproductive health but can easily be modified.

•        Smoking - has been linked to reduced egg reserves and lower egg quality in women,⁵ while in men, it’s associated with decreased sperm quality and motility.⁶
•        Alcohol - consumption may lower fertility and lead to poorer pregnancy outcomes.⁷ In men, it can reduce libido and sperm count.⁸
•                Caffeine - women who drink more than one cup of coffee a day may be half as likely to conceive per cycle compared to those who drink less.⁹
•        Stress - and reduced quality of life are also known to negatively affect fertility in women.¹⁰

The B Vitamin Complex: Your Fertility Allies

Vitamin B encompasses eight distinct water-soluble compounds collectively referred to as the B vitamin complex. Although B vitamins typically work better together, each has its own essential functions. Growing research highlights the key role of B vitamins in reproductive health, showing that targeted nutritional support can positively impact fertility outcomes. Here’s how B vitamins may help on your fertility journey.

Vitamin B1 (Thiamine)

• By supporting the nervous system and energy production, thiamine helps maintain key functions that play a role in reproductive health and overall well-being in both men and women
• Food Sources: Nuts, seeds, meat, beans and peas

Vitamin B2  (Riboflavin)

• Riboflavin contributes to the maintenance of normal red blood cells and helps protect cells from oxidative stress - key factors in supporting both male and female reproductive health. Its role in energy metabolism and antioxidant protection is also important for sperm health and oocyte maturation.
• Food Sources: Milk, eggs, mackerel, sardines, mushrooms, almonds

Vitamin B3 (Niacin)

•        Niacin is another B vitamin that contributes to normal energy metabolism, which is vital for reproductive processes like ovulation, sperm production and embryo development — all of which have high energy requirements.

•        Food Sources: Meat, poultry, fish, wholegrains (brown rice, bread, quinoa, pasta), peanuts, seeds

Vitamin B5 (Pantothenic Acid)

•        Pantothenic acid contributes to normal mental performance and energy metabolism, supporting the body’s resilience to stress—an important factor in hormone regulation and fertility. It also plays a key role in the synthesis and metabolism of steroid hormones, which are essential for maintaining hormonal balance and healthy reproductive function.

•        Food Sources: Avocado, dairy products, egg yolks, poultry, meat, wholegrains, sweet potato, lentils, split peas, mushrooms, nuts, seeds

Vitamin B6 (pyridoxine)

•        Vitamin B6 contributes to the regulation of hormonal activity, supporting balance in key reproductive hormones such as progesterone—essential for ovulation and maintaining a healthy menstrual cycle. It also contributes to homocysteine metabolism, a vital part of the methylation cycle that underpins DNA synthesis, detoxification, and reproductive health. Because it also helps to reduce fatigue and contributes to the regulation of hormonal activity and psychological function, vitamin B6 may influence libido and overall sexual well-being.

•        Food Sources: Oats, bananas, milk, soya beans, peanuts, wheatgerm, pork, poultry, some fish, yeast extract, sesame seeds, avocado, green peppers

Biotin (vitamin B7)

•        By contributing to nervous system and psychological function, biotin plays a role in mood balance and neurological function which helps to support hormonal health, libido and a relaxed mind and body – all relevant for fertility
•        Food Sources: Cooked egg yolks, organ meats, nuts, seeds, peanuts, soybeans, lentils, whole grains, sweet potatoes, mushrooms, bananas, avocados

Folate (vitamin B9)

•        Folate contributes to maternal tissue growth during pregnancy, supports normal cell division, and plays a key role in DNA synthesis—making it essential for egg quality, early foetal development, ovulation, and implantation. For male reproductive health, folate contributes to normal homocysteine metabolism, which is associated with sperm quality and the protection of DNA from damage.

•        Food Sources: Green leafy vegetables, malted and brown bread, offal, peas, beans, oranges, berries, broccoli, Brussels sprouts, chickpeas

Vitamin B12 (Cobalamin)

•        Vitamin B12 supports energy metabolism and reduces fatigue, which can be helpful during the menstrual cycle or when trying to conceive. It contributes to psychological and nervous system function, supporting hormonal balance and emotional well-being. B12 also aids normal cell division - a fundamental process for sperm production, ovulation, and implantation. Additionally, B12 contributes to homocysteine metabolism, supporting overall cellular health, an important foundation for fertility in both men and women.

•        Food Sources: Meat, fish, shellfish, milk, cheese, eggs, yeast extract, fortified foods like nutritional yeast, breakfast cereals and plant milk

Natural Ways To Boost Fertility With B Vitamins

When it comes to supporting fertility naturally, food-sourced B vitamins are a great place to start. Not only are they more easily absorbed by the body, but they also come packaged with natural cofactors that support their function. It’s also worth remembering that it takes around three months for immature eggs to develop before ovulation and the same timeframe applies to sperm development in men. That’s why it’s a good idea to start nourishing your body well in advance. Try some of these balanced meal ideas :

• Breakfast: Whole grain cereal with milk, topped with seeds and berries
• Lunch: Leafy green salad with eggs, avocado, and walnuts
• Dinner: Fish, lean meat or beans with whole grains and steamed vegetables
• Snacks: Yogurt with sliced banana, or vegetable sticks with hummus

When to Take Supplements

While food should be your primary source of B vitamins, certain circumstances may warrant supplementation:

• During preconception planning
• If you have dietary restrictions (such as vegetarian or vegan diets)
• When specific health conditions affect nutrient absorption
• If you have a common gene variant (MTHFR) that makes it harder to process folic acid. Taking folate in its active form (L-methylfolate), can better support fertility, hormone balance, and a healthy pregnant

Whether you’re trying to conceive naturally or preparing for assisted conception, supporting your body with B vitamins and healthy lifestyle choices can make a real difference and empower your fertility journey.

Written by: Jacqueline Newson BSc (Hons) Nutritional Therapy

Edited by: Alejandra Toro, Pshychologist, MSc Nutrition and Behaviour  

REFERENCES

1.         WHO.1 in 6 people globally affected by infertility. 1 in 6 people globally affected by infertility. https://www.who.int/news/item/04-04-2023-1-in-6-people-globally-affected-by-infertility?utm_source=chatgpt.com. [accessed 10.04.25.]

2.         Maitin-Shepard M et al. Food, Nutrition, and fertility: from soil to fork. The American Journal of Clinical Nutrition 119 (2024) 578–589.

3.       Tomada I, Tomada N. Mediterranean Diet and Male Fertility. Endocrines. 2023; 4(2):394-406. https://doi.org/10.3390/endocrines4020030.

4.        Simon Alesi, et al. Assessing the influence of preconception diet on female fertility: a systematic scoping review of observational studies, Human Reproduction Update, Volume 29, Issue 6, November-December 2023, Pages 811–828, https://doi.org/10.1093/humupd/dmad018.

5.       NIH. What Lifestyle and environmental factors may be involved with infertility in females and males? https://www.nichd.nih.gov/health/topics/infertility/conditioninfo/causes/lifestyle. [Acessed 10.04.25.]

6.        Sharma, R., Biedenharn, K.R., Fedor, J.M. et al. Lifestyle factors and reproductive health: taking control of your fertility. Reprod Biol Endocrinol 11, 66 (2013). https://doi.org/10.1186/1477-7827-11-66.

7.       NIH. What Lifestyle and environmental factors may be involved with infertility in females and males? https://www.nichd.nih.gov/health/topics/infertility/conditioninfo/causes/lifestyle. [Acessed 10.04.25.]

8.        Sharma, R., Biedenharn, K.R., Fedor, J.M. et al. Lifestyle factors and reproductive health: taking control of your fertility. Reprod Biol Endocrinol 11, 66 (2013). https://doi.org/10.1186/1477-7827-11-66.

9.      Wilcox A, Weinberg C, Baird D. Caffeinated beverages and decreased fertility. Lancet. 1988 Dec 24-31;2(8626-8627):1453-6. doi: 10.1016/s0140-6736(88)90933-6. PMID: 2904572.

10.    Palomba, S., Daolio, J., Romeo, S. et al. Lifestyle and fertility: the influence of stress and quality of life on female fertility. Reprod Biol Endocrinol 16, 113 (2018). https://doi.org/10.1186/s12958-018-0434-y.