Parents all know that sun-dried synthetic vitamin D, but they have to apply sunscreen to their children in summer, so there has always been a saying on the Internet that wearing sunscreen will affect children's absorption of vitamin D.
Is it true?
1. Does wearing sunscreen affect vitamin D synthesis?
Theoretically, this is possible!
In the past, laboratory studies have shown that giving children sunscreen may affect the synthesis of vitamin D in the body.
However, theory is theory, and in practical life, due to the interference of various factors, it is impossible to perfectly achieve the conditions required by theory.
In recent years, more and more field trials and observational studies have also found that the likelihood of affecting vitamin D synthesis after applying sunscreen is very low.
This is mainly due to:
On the one hand, when parents apply sunscreen to their children, there is no way to be "perfect". For example, there may be cases where you don't apply enough amount, don't reapply on time, or omit (e.g., feet, neck, etc.).
All of these conditions can make the sunscreen much less effective and less effective.
On the other hand, the SPF value of a sunscreen determines its ability to resist UVB rays (UVA, UVB and UVC) in UVB, and the higher the SPF value, the more UVB is blocked.
图源:Pexels
Since UVB can interact with 7-dehydrocholesterol in our skin to synthesize vitamin D, the SPF value of sunscreen also indirectly affects the synthesis of vitamin D.
However, even sunscreens with an SPF of 50 have a UVB coverage rate of only 98%, which cannot completely block UVB absorption by the skin, and naturally cannot block the synthesis of vitamin D in children's bodies.
In other words, whether it is for the sunscreen itself or the irregular practices of parents when using sunscreen, there is no way for sunscreen to completely cut off the connection between ultraviolet rays and children's skin, and there is no way to completely prevent the synthesis of vitamin D in children's bodies.
All in all, the daily use of sunscreen has a negligible effect on vitamin D synthesis, and it is difficult to directly cause vitamin D deficiency in children.
2. Is it okay to supplement vitamin D only by basking in the sun?
Since wearing sunscreen every day does not have much impact on the synthesis of vitamin D in children, many parents may wonder, is it okay to supplement vitamin D by basking in the sun every day without taking supplements?
Unfortunately, not really!
On the one hand, while wearing sunscreen won't have much of an effect on vitamin D synthesis, it doesn't mean there isn't any effect at all.
On the other hand, it is because, for parents, relying on sun exposure to supplement their children with vitamin D, there are too many uncontrollable factors.
For example, as mentioned above, it can help children synthesize vitamin D's ultraviolet rays.
图源:Pexels
UVB only accounts for 5%~10% of the ultraviolet rays that our skin can be exposed to, and its proportion will also be affected by multiple environmental factors such as weather, latitude, climate, and altitude where the child is located.
For example, during the same summer, children living in Harbin are not exposed to UVB as much as children living in Haikou.
Children living in Harbin are not exposed to UVB in winter as much as they can in summer.
Under the influence of these environmental factors, children will inevitably get tanned in the sun, but when checked, they are still deficient in vitamin D.
In addition, the clothes worn by children, the sun through the glass at home, and the time and duration of sun exposure may also affect the effect of vitamin D supplementation in the sun.
Therefore, for children, the most reliable and stable way to supplement vitamin D is oral vitamin D supplements!
Parents should definitely apply sunscreen to their children when they take them out to play to reduce the risk of skin cancer!
However, it should be noted that do not wrap the child's inner and outer three layers with clothes, otherwise it will still lead to various diseases of vitamin D deficiency in the child, such as osteoporosis and increased risk of cognitive impairment.
Daily vitamin D supplementation, and don't rely only on sun exposure, oral supplements are more stable.