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Pregnancy is a period when a woman’s body works twice as hard, providing not only for its own needs but also for the development of new life. Even a natural phenomenon like sunlight can affect the course of pregnancy both positively and negatively. It is important to understand when the sun is an ally and when it is a risk factor.
Why is the sun beneficial during pregnancy?
Under the influence of ultraviolet radiation (UVB rays), vitamin D₃ (cholecalciferol) is synthesized in the skin. This is one of the key nutrients for a healthy pregnancy.
Main benefits of vitamin D₃ for the expectant mother and the fetus:
- Supports proper formation of the fetal skeletal system
- Maintains the woman’s immune system
- Reduces the risk of gestational diabetes, preeclampsia, bacterial vaginosis
- Positively influences brain development in the child
Even 15–20 minutes in the sun daily can provide a basic level of vitamin D. But there is an important point that is often forgotten.
When can the sun be harmful during pregnancy?
Sunlight destroys folates
The same ultraviolet light that stimulates vitamin D production has a side effect — it destroys folates (vitamin B9) in the skin and blood.
This is critically important because folates:
- Protect against neural tube defects in the fetus (spina bifida, anencephaly)
- Play a central role in DNA synthesis and cell division
- Support normal placenta formation
Folate deficiency in the first trimester is a serious risk. That is why excessive sun exposure without protection can be dangerous.
Genetics and skin type: why are some women more vulnerable?
Skin phenotype and genetic characteristics affect how the body responds to ultraviolet light. For example:
- Women with fair skin (phototype I–II) have a higher risk of folate loss because their skin is less protected from UV rays
- Women with the MTHFR C677T mutation (common in Eastern Europe) have impaired conversion of folic acid into its active form (5-MTHF). In this case, sun exposure further depletes folate reserves
According to a study published in “Nature Communications” (2023), women with a combination of low folate levels and high sun exposure in the first trimester had a significantly increased risk of congenital defects in the fetus.
Other risks of excessive sun exposure during pregnancy
- Increased oxidative stress
UV rays increase the formation of free radicals that damage DNA, placental cells, and blood vessels. - Reduction of vitamin B2 (riboflavin) levels
This vitamin is important for energy metabolism, antioxidant protection, and support of fetal tissue development. - Skin photosensitivity and pigmentation
Under the influence of estrogen, melanocytes — cells responsible for pigment formation — are activated in pregnant women. This results in pigment spots, especially on the face (melasma).
Which nutrients help the body cope with ultraviolet light?
Antioxidant support from within
Oxidative stress is neutralized by antioxidants. The most important among them:
Vitamin C — stimulates collagen synthesis, supports tissues, reduces the risk of rupture of fetal membranes
Vitamin E — protects cell membranes from damage
Selenium and zinc — activate enzymes that neutralize free radicals
Folates in the form of 5-MTHF — the best form for pregnant women, especially with genetic mutations
Riboflavin (B2) — reduces oxidative stress, supports overall metabolism
The daily diet of a pregnant woman should include green vegetables, berries, eggs, nuts, lean meat, whole grains, as well as nutrients in supplement form as recommended by a doctor.
How to protect yourself from the sun during pregnancy safely and effectively?
External sun protection: which SPF is suitable for pregnant women?
Due to increased photosensitivity, the use of sunscreen is mandatory for pregnant women.
- SPF no lower than 30, ideally 50+
- Broad-spectrum: protection from UVA and UVB
- Physical (mineral) filters: zinc oxide or titanium dioxide
- Avoid chemical filters such as oxybenzone or octinoxate — they may affect the hormonal system
Protection should be reapplied every 2 hours, as well as after swimming or heavy sweating.
Additional measures: wear lightweight clothing with long sleeves, wide-brimmed hats, and sunglasses.
Hydration
During heat and sun exposure, the body loses more fluids. Dehydration in pregnant women can cause headaches, weakness, impaired placental blood flow, and in critical cases — preterm labor.
What to do:
- Drink at least 2.3–2.5 liters of fluid per day
- In hot weather, monitor urine color — it should be light
- Beneficial not only water but also natural sugar-free compotes, rosehip decoctions, herbal teas (approved by a doctor)
Recommendations in a table
| Recommendation | Details |
|---|---|
| Sun exposure | 15–20 minutes daily at safe times: before 11:00 and after 16:00 |
| Sun protection | SPF 50+, physical filters, reapply every 2 hours |
| Supplements | Folic acid — preferably as metafolin or methylfolate (400–800 mcg/day), vitamins C, E, B2, zinc, selenium |
| Clothing | Light covered clothing, hats, sunglasses |
| Fluids | 2.3–2.5 liters per day, more in hot weather |
Conclusion:
The sun is a natural source of energy, warmth, and vitamin D, which is extremely important for a healthy pregnancy. However, excessive UV exposure can destroy folates, increase oxidative stress, and negatively affect fetal development.
To benefit from the sun without risks:
- Limit sun exposure to short periods during safe hours,
- Always use sunscreen with mineral filters,
- Support your body with antioxidant nutrients,
- Do not forget regular hydration and a balanced diet,
- And, if possible, check your genetic profile for mutations (e.g., MTHFR) that may affect folate metabolism.
Remember: the sun is necessary, but in moderation. Balancing benefits and safety is the best choice for you and your future child.
