Supporting Your Immunity During Pregnancy
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With infections rife, we need to protect the vulnerable members of our community, including mums-to-be. It’s difficult to navigate your way through the do’s and don’ts of pregnancy at the best of times, let alone trying to maintain a strong immune system too! So read on to learn about our top tips for optimising immunity during pregnancy which we hope you find helpful and reassuring.

Immunity during Pregnancy

You might not realise it but pregnancy alters the immune system. To ensure a viable pregnancy, the maternal immune system has to accept the growing baby as ‘self’ rather than ‘foreign’. It does this by ‘turning down’ the side of the immune system involved in mounting a response against foreign threats (e.g. bacteria, viruses, abnormal cells) to the degree required to ensure immune tolerance of the growing baby.[i] This adaptation should still leave the mother with sufficient immunity to fight off infection, however it is often further weakened by the stresses and strains of the modern world which can make pregnant women vulnerable to infection.

Pregnancy is nutrient demanding. A hefty daily supply of nutrients is required to simultaneously support foetal development and maintain the health of mum. This high nutrient ‘demand’ needs to be matched by a high nutrient ‘supply’ to ensure that mum and baby are well-supported, but this often isn’t the case. Nutritional insufficiencies/deficiencies are all too common during pregnancy, such as vitamin D, iodine, folate, and iron,[ii] driven by a combination of factors, not least over-consumption of micronutrient-depleted, over-processed foods, poor digestion (especially if there are underlying digestive issues), and/or indoor lifestyles. Stress also has a negative impact on immunity during pregnancy,[iii] as it does for every life stage!

It is important to recognise that knowledge of how the immune system functions and changes throughout pregnancy, including during infection, is rapidly developing.[iv],[v],[vi],[vii] So, it is essential to tread carefully when it comes to supporting immunity during this life stage, especially when it comes to supplementation.[viii]

Nutrition: What You Can Safely Do

A great starting point is a therapeutic pregnancy multinutrient to ensure an optimal baseline intake of immune-supportive nutrients, particularly vitamin A, C, D, and zinc.

You may ask, “Aren’t I meant to avoid vitamin A during pregnancy?”As with any nutrient, you can have too much or too little, and vitamin A deficiency can be just as detrimental as toxicity. It is vital to embryo development[ix] and immune response,[x],[xi] and neonatal vitamin A deficiency is a risk factor for infectious diseases (e.g. measles).[xii] A total daily intake of preformed vitamin A (e.g. retinol) greater than 10,000 IU per day is associated with negative foetal health outcomes,[xiii] but this does not mean that it should be avoided, especially when you consider its physiological significance. A conservative daily dose of c. 2000 IU per day is appropriate during pregnancy to get the best of both worlds, especially for immune support. Also increase your intake of provitamin A (e.g. beta carotene) from colourful foods such as carrots and greens (e.g. kale),[xiv] served with a source of fat to support absorption (e.g. olive oil). The body will convert this to preformed vitamin A on an as-needed basis.

Alongside a multinutrient, it can be prudent to further increase your intake of the following nutrients to ensure therapeutic immune support:

  • Vitamin C has well-demonstrated efficacy against viral infection[xv] and may reduce the incidence and severity of pneumonia.[xvi] It may also be protective against urinary tract infections too,[xvii] an otherwise common complaint for mums-to-be.
    • The upper limit for vitamin C during pregnancy is 1800mg per day.
    • This means there’s scope to take more supplemental vitamin C per day, especially if fighting an infection. To discuss if this is appropriate for you though, we recommend that you contact our Clinical Nutrition team.
  • Vitamin D enhances our natural immune response against infection, including flu and respiratory tract infections.[xviii] As such, vitamin D deficiency can increase risk of infection.[xix] It has also been shown to increase the risk of pregnancy complications such as preeclampsia, gestational diabetes, emergency C-section delivery, low birth weight,[xx] recurrent pregnancy loss[xxi] and postpartum depression,[xxii] so all the more reason to optimise levels during pregnancy. A daily supplemental dosage of 1000IU vitamin D3 is a great starting point, alongside an increased dietary intake (e.g. eggs, mushrooms).
    • The upper limit for vitamin D during pregnancy is 4000 IU per day.
    • To determine whether you need to take a higher dosage, it is a good idea to get your vitamin D levels tested through the GP or via a private finger-prick test. If you let our Clinical Nutrition team know your result, they can advise you about a supplemental dosage tailored to your needs.
  • Zinc can boost immune cell activity,[xxiii] inhibit viral replication,[xxiv] and shorten the duration of colds.[xxv]
    • The upper limit for zinc during pregnancy is 34mg per day.
    • You could therefore add an extra 15mg zinc on top of your multinutrient (which usually contains around 15mg) for additional immune support as necessary on a short-term basis (e.g. 1-3 months).
  • Probiotics work synergistically alongside the above nutrients to strengthen immunity, especially with respect to respiratory health. For instance, Lactobacillus and Bifidobacterium strains can reduce the risk of upper respiratory tract infections.[xxvi] The LAB4B blend of Lactobacillus salivarius, Lactobacillus paracasei, Bifidobacterium bifidum, and Bifidobacterium lactis was used in the Swansea Baby Study in a group of pregnant women and their newborn babies at a total daily dosage of 10 billion. Not only was it safe to take, it reduced the risk of atopy in the offspring too,[xxvii] demonstrating additional immune benefits! Given the prevalence of constipation during pregnancy, a daily probiotic may help to maintain bowel regularity as well.[xxviii] This can be achieved through a well-researched supplement and foods such as kefir, live yoghurt, and raw sauerkraut.
  • Magnesium aids stress management and sleep quality.[xxix],[xxx] Given the prevalence of high stress and poor sleep during pregnancy, and their negative impact on immunity, magnesium can be another helpful nutrient to increase your intake of.
    • The upper limit for magnesium during pregnancy is 350mg per day.
    • We usually work up to this higher dosage through supplementation when therapeutic calming support is required, typically in the –citrate form which is helpful for bowel regularity too.[xxxi] Also increase your daily intake of magnesium from foods such as nuts and seeds, spinach, kale, and chocolate (consumed in moderation, mind you!).

The Power of Lifestyle

When pregnant, a lot can feel out of our control. This can put additional strain on our stress levels, which can then weaken immunity. We’re keen to encourage you to focus on all that you can control – your nutrition as mentioned above, and lifestyle too. Keep it simple and focus on the below:

  • Relaxation and sleep are just as important as nutrition to maintaining a strong immune system,[xxxii] but can be a rarity during pregnancy! Given how energy demanding pregnancy is, it is especially important to prioritise rest during this life stage. In addition to the classic suggestions (e.g. wearing an eye mask, regular sleep-wake routine, avoiding technology in the hour before bed), explore the following:
    • Create a sanctuary space where you go for ‘you-time’. It could be a comfy chair with a gorgeous cushion and aromatherapy candle. Establish a daily routine of retreating to this space to practice a relaxation technique which you love, such as meditation, reading fiction, singing, or listening to music.
    • Incorporate a nap into your day to give your body extra time to rest and repair. Yes, you heard us right – we’re asking you to nap!
  • Move – gentle daily exercise is essential during pregnancy to support circulation of nutrients and boost mental health[xxxiii] and immunity.[xxxiv] Go for walk in the park or woods, or prenatal yoga – if you can’t get to a class, there are a range of great classes on YouTube which you could try, often for free!

For tailored advice, get in touch with our Clinical Nutrition team who will be more than happy to help you. Stay safe and wishing you the best of health!

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[i] Morelli, S., et al. The maternal immune system during pregnancy and its influence on fetal development. Research and Reports in Biology. 2015; 6: 171-189.

[ii] Becker, W et al. Dietary habits, nutrient intake and biomarkers for folate, vitamin D, iodine and iron status among women of childbearing age in Sweden. Upsala Journal of Medical Sciences. 2016; 121(4): 271-275.

[iii] Christian, L. Stress and Immune Function During Pregnancy. Current Directions in Psychological Science. 2015; 24(1): 3-9.

[iv] Racicot, K., Mor, G. Risks associated with viral infections during pregnancy. Journal of Clinical Investigation. 2017; 127(5): 1591-1599.

[v] Silasi, M., et al. Viral Infections During Pregnancy. American Journal of Reproductive Immunology. 2015; 73(3):199-213.

[vi] Memoli, M., et al. Influenza in pregnancy. Influenza and Other Respiratory Viruses. 2012;, 7(6): 1033-1039.

[vii] Robertson, C., et al. SARS and Pregnancy: A Case Report. Emerging Infectious Diseases. 2004; 10(2): 345-348.

[viii] Brown, B., Wright, C. Safety and efficacy of supplements in pregnancy. Nutrition Reviews. 2020 [Epub ahead of print]

[ix] Gutierrez-Mazariegos J et al. Vitamin A: a multifunctional tool for development. Semin Cell Dev Biol. 2011; 22 (6): 603-10.

[x] Huang Z et al. Role of vitamin A in the immune system. J Clin Med. 2018; 7 (9): 258.

[xi] Iyer N, et al. Vitamin A at the interface of host-commensal-pathogen interactions. PLoS Pathog. 2019; 15 (6): e1007750.

[xii] Katona P, Katona-Apte J. The interaction between nutrition and infection. Clin Infect Dis. 2008; 46 (10): 1582-8.

[xiii] Bastos MS et al. Vitamin A and pregnancy: a narrative review. Nutrients. 2019; 11 (3): 681.

[xiv] Mateljan, G., 2020. Vitamin A. [online]

[xv] Hemilä H. Vitamin C and SARS coronavirus. Journal of Antimicrobial Chemotherapy. 2003; 52 (6): 1049-1050.

[xvi] Hemilä H, Chalker E. Vitamin C Can Shorten the Length of Stay in the ICU: A Meta-Analysis. Nutrients. 2019; 11(4): 708.

[xvii] Ochoa-Brust GJ, et al. Daily intake of 100 mg ascorbic acid as urinary tract infection prophylactic agent during pregnancy. Acta Obstet Gynecol Scand. 2007; 86:783–787.

[xviii] Yamshchikov et al. Vitamin D for treatment and prevention of infectious diseases: a systematic review of randomized controlled trials. Endocrine Practice. 2009; 15 (5): 438-49.

[xix] Ginde AA, Mansbach JM, Camargo CA. Association between serum 25-hydroxyvitamin D level and upper respiratory tract infection in the Third National Health and Nutrition Examination Survey. Arch Intern Med. 2009; 169 (4): 384-90.

[xx] Van der Pligt P, et al. Associations of maternal vitamin D deficiency with pregnancy and neonatal complications in developing countries: a systematic review. Nutrients. 2018; 10:640–661.

[xxi] Goncalves DR, Braga,et al. Recurrent pregnancy loss and vitamin D: a review of the literature. Am J Reprod Immunol. 2018; 80:e13022.

[xxii] Wang J, Liu N, et al. Association between vitamin D deficiency and antepartum and postpartum depression: a systematic review and meta-analysis of longitudinal studies. Arch Gynecol Obstet. 2018;298:1045–1059.

[xxiii] Caballero B, Allen L, Prentice A (eds.). Encyclopedia of Human Nutrition. Academic Press, San Diego, pp.447-454.

[xxiv] Turner RB. The treatment of rhinovirus infections: progress and potential. Antiviral Res. 2001; 49:1-14.

[xxv] Goutham R, Rowland K. Zinc for the common cold – not if, but when. J Fam Pract. 2011; 60 (11): 669-671.

[xxvi] Garaiova I et al. Probiotics and vitamin C for the prevention of respiratory tract infections in children attending preschool: a randomised controlled pilot study. European Journal of Clinical Nutrition. 2015; 69: 373-379.

[xxvii] Allen SJ et al. Probiotics in the prevention of eczema: a randomised controlled trial. Arch Dis Child. 2014; 99 (11): 1014-1019.

[xxviii] Mirghafourvand M et al. The effect of probiotic yoghurt on constipation in pregnant women: a randomized controlled clinical trial. Iran Red Crescent Med J. 2016; 18 (11): e39870.

[xxix] Held et al. Oral Mg (2+) supplementation reverses age-related neuroendocrine and sleep EEG changes in humans. Pharmacopsychiatry. 2002; 35 (4): 135-43.

[xxx] Abbasi et al. The effect of magnesium supplementation on primary insomnia in elderly: A double-blind placebo-controlled clinical trial. J Res Med Sci. 2012 Dec; 17 (12): 1161-9

[xxxi] Manes et al. Randomized controlled trial comparing efficacy and acceptability of split- and standard-dose sodium picosulfate plus magnesium citrate for bowel cleansing prior to colonoscopy. Endoscopy. 2014. Aug; 46 (8): 662-9.

[xxxii] Cohen S et al. Sleep habits and susceptibility to the common cold. Arch Intern Med. 2009; 169 (1): 62-7.

[xxxiii] Sharma A, Madaan V, Petty FD. Exercise for mental health. Prim Care Companion J Clin Psychiatry. 2006; 8 (2): 106.

[xxxiv] Nieman DC, Wentz LM. The compelling link between physical activity and the body’s defense system. Journal of Sport and Health Science. 2019; 8 (3): 201-217.

April 1, 2020
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