Deficiency in this vitamin is very common.
Higher vitamin D levels during pregnancy are linked to higher IQ among children, research finds.
Unfortunately, vitamin D deficiency is common in the general population and especially among Black people.
Around 80 percent of Black pregnant women may be deficient in vitamin D.
Ms Melissa Melough, the study’s first author, explains:
“Melanin pigment protects the skin against sun damage, but by blocking UV rays, melanin also reduces vitamin D production in the skin.
Because of this, we weren’t surprised to see high rates of vitamin D deficiency among Black pregnant women in our study.
Even though many pregnant women take a prenatal vitamin, this may not correct an existing vitamin D deficiency.
I hope our work brings greater awareness to this problem, shows the long-lasting implications of prenatal vitamin D for the child and their neurocognitive development, and highlights that there are certain groups providers should be paying closer attention to.
Widespread testing of vitamin D levels is not generally recommended, but I think health care providers should be looking out for those who are at higher risk, including Black women.”
The study included over 1,500 women and their children, who were tracked over five years.
The results showed that children had higher IQs at 4-6 years old when their mothers had higher vitamin D levels during pregnancy.
Ms Melough said:
“Vitamin D deficiency is quite prevalent.
The good news is there is a relatively easy solution. It can be difficult to get adequate vitamin D through diet, and not everyone can make up for this gap through sun exposure, so a good solution is to take a supplement.”
The recommended daily intake for vitamin D is 600 IU.
The average intake in the US is just 200 IU, with the remainder required from exposure to the sun.
Unfortunately, most people do not get enough exposure to the sun, especially in the winter months.
Foods that contain high levels of vitamin D include cow’s milk, breakfast cereals, fatty fish and eggs.
Ms Melough said:
“I want people to know that it’s a common problem and can affect children’s development.
Vitamin D deficiency can occur even if you eat a healthy diet.
Sometimes it’s related to our lifestyles, skin pigmentation or other factors outside of our control.”
The study was published in The Journal of Nutrition (Melough et al., 2020).
