According to new research, getting enough vitamin D during pregnancy can have a big impact on your baby’s future health and may even affect fertility in sons.
Vitamins in pregnancy
During pregnancy, your body undergoes significant physiological changes, including an increased need for nutrients to support your baby’s growth and development. Vitamins are essential nutrients that play a vital role in maintaining maternal and foetal health. Therefore, it is important for pregnant women to eat a balanced and varied diet that includes a wide range of vitamins to meet their increased nutrient needs during pregnancy. In addition, healthcare providers may recommend prenatal supplements to help ensure adequate vitamin intake during pregnancy.
Vitamin D
Vitamin D is an important nutrient that plays many roles in the body. Some of its key functions include helping the body absorb calcium from food (which is necessary for strong bones and teeth), regulating the immune system, supporting muscle function, regulating mood and insulin levels, and even protecting against certain types of cancer.
We get vitamin D when our skin is exposed to sunlight. Our bodies can then produce vitamin D3. However, the amount of vitamin D your skin produces depends on factors such as time of day, latitude and skin pigmentation. In some cases, you may not be able to get enough vitamin D from sunlight alone and may need to supplement with food sources.
Food sources of vitamin D include fatty fish such as salmon, tuna and mackerel, and fish liver oils. Small amounts of vitamin D are also found in egg yolks, beef liver and cheese. Some foods, such as milk, orange juice and cereals, can be fortified with vitamin D.
Supplements are also a common way to get vitamin D. Vitamin D supplements come in different forms, including tablets, capsules and drops. Vegans can choose special vegan vitamin D supplements. These contain vitamin D from lichens.
You can find out how much vitamin D you have by having a simple blood test done by your doctor. Normal levels of vitamin D in the blood can vary depending on the laboratory and method of measurement. However, the following are general guidelines:
– A blood vitamin D level of 30 to 50 nanograms per millilitre (ng/ml) is considered adequate.
– A level below 20 ng/ml is considered to be vitamin D deficient.
– A level between 20 and 30 ng/ml is called vitamin D insufficiency.
It is important to note that these guidelines do not apply to everyone. For example, older people, people with darker skin and people who get little sunlight may need higher levels of vitamin D to stay healthy.
How common is vitamin D deficiency?
Vitamin D intake in the general population can vary depending on several factors, including geography, season, age and lifestyle. In general, many people do not get enough vitamin D from sunlight alone, and dietary sources may be inadequate.
In addition, some people may have medical conditions or take medicines that affect their ability to absorb vitamin D or convert it to its active form. Medications that increase vitamin D requirements include:
- antiepileptics
- laxatives
- metformin
- loop diuretics
- angiotensin-converting enzyme inhibitors
- thiazide diuretics
- statins
- calcium channel blockers
- vitamin K antagonists
- antiplatelet agents
- digoxin
- potassium-sparing diuretics
- benzodiazepines
- antidepressants
- proton pump inhibitors
- histamine H2-receptor antagonists
- bile acid sequestrants
- corticosteroids
- antimicrobials
- sulfonamides and urea derivatives
- lipase inhibitors
- hydroxychloroquine
- highly active antiretrovirals
- certain chemotherapeutic agents
Research suggests that vitamin D deficiency is relatively common, particularly among people with darker skin tones, those living in northern latitudes, and women. According to the National Health and Nutrition Examination Survey (NHANES), about 40% of Americans have vitamin D levels below the recommended range. In Central Europe, the German National Consumption Survey II showed that over 80% of the population do not get enough vitamin D from food.
Vitamin D in pregnancy
Adequate vitamin D levels during pregnancy have been linked to a lower risk of certain pregnancy complications, such as pre-eclampsia and gestational diabetes.
Importantly, vitamin D also plays a key role in the development of your baby, and maternal vitamin D status during pregnancy has been shown to have an important impact on the future health of your child. Healthy vitamin D levels during pregnancy have been linked to improved bone health in your baby, a reduced risk of infection and a possible reduced risk of chronic diseases in later life, such as asthma and allergies. Research has also suggested that maternal vitamin D status may influence fetal brain development.
Maternal vitamin D level and offspring fertility
A recent study published in the journal Andrology has found that maternal vitamin D levels during pregnancy may even play an important role in male reproductive health.
The study followed 827 Danish young men to investigate whether maternal vitamin D levels were associated with measures of reproductive health in adult sons.
The researchers measured semen characteristics, testicular volume and reproductive hormone levels in the adult sons and analysed them according to maternal vitamin D levels during pregnancy.
The study found that sons of mothers with vitamin D levels below 25 nmol/L had 11% lower testicular volume and a 1.4 times higher risk of low testicular volume (less than 15 mL) compared with sons of mothers with vitamin D levels above 75 nmol/L. They also had a 20% lower total sperm count and a 1.6 times higher risk of having a low total sperm count (less than 39 million) compared to sons of mothers with higher vitamin D levels.
The findings suggest that maternal vitamin D levels above 75 nmol/L during pregnancy may be beneficial for testicular function in adult sons.
This study highlights the importance of maternal vitamin D levels during pregnancy for the long-term reproductive health of male offspring. Further research is needed to confirm these findings and explore the underlying mechanisms. However, it suggests that you should consider maintaining adequate vitamin D levels during pregnancy to support the health of your unborn child.
The American College of Obstetricians and Gynaecologists recommends that pregnant women get at least 600-800 IU of vitamin D a day. However, many women may need higher doses to achieve adequate levels of vitamin D, especially if they have limited sun exposure or do not get enough vitamin D-rich foods.
What to do?
If you are pregnant, talk to your doctor about your individual vitamin D needs during pregnancy. You may want to consider having your vitamin D levels checked to make sure they are within a healthy range. If you take prenatal vitamins, make sure they contain at least 20 µg (= 800 IU) of vitamin D
Sources:
Aiyong Cui, Peilun Xiao, Yuzhuo Ma, Zhiqiang Fan, Fengjin Zhou, Jiang Zheng and Liang Zhang. Prevalence, trend, and predictor analyses of vitamin D deficiency in the US population, 2001–2018. Front. Nutr., 03 October 2022 Sec. Nutritional Epidemiology Volume 9 – 2022 | https://doi.org/10.3389/fnut.2022.965376
Fatima K, Asif M, Nihal K, Hussain HU, Hasan AW, Zahid M, Burney MH, Asad F, Fatima S, Saleem MB, Khalid MA. Association between vitamin D levels in early pregnancy and gestational diabetes mellitus: A systematic review and meta-analysis. J Family Med Prim Care. 2022 Sep;11(9):5569-5580. doi: 10.4103/jfmpc.jfmpc_107_22. Epub 2022 Oct 14. PMID: 36505566; PMCID: PMC9731084.
Gaml-Sørensen A, Brix N, Hærvig KK, Lindh C, Tøttenborg SS, Hougaard KS, Høyer BB, Ernst A, Arendt LH, Clemmensen PJ, Bonde JPE, Henriksen TB, Toft G, Arah OA, Ramlau-Hansen CH. Maternal vitamin D levels and male reproductive health: a population-based follow-up study. Eur J Epidemiol. 2023 Mar 23. doi: 10.1007/s10654-023-00987-5. Epub ahead of print. PMID: 36952117.
Malm G, Lindh CH, Hansson SR, Källén K, Malm J, Rylander L. Maternal serum vitamin D level in early pregnancy and risk for preeclampsia: A case-control study in Southern Sweden. PLoS One. 2023 Feb 7;18(2):e0281234. doi: 10.1371/journal.pone.0281234. PMID: 36749741; PMCID: PMC9904465.
Wakeman M. A Literature Review of the Potential Impact of Medication on Vitamin D Status. Risk Manag Healthc Policy. 2021 Aug 14;14:3357-3381. doi: 10.2147/RMHP.S316897. PMID: 34421316; PMCID: PMC8373308.
https://www.mri.bund.de/fileadmin/MRI/Institute/EV/NVSII_Abschlussbericht_Teil_2.pdf
