Vitamin D is a fat-soluble vitamin required by all living beings for bone health, calcium absorption, and brain function. This vitamin is also known as calciferol.
Most of the vitamin D is obtained naturally from sunlight. While melanin (the skin pigment) protects the skin from the harmful effects of ultraviolet rays, excess melanin can also hinder the absorption of vitamin D from the sunlight.
According to a study published in the Journal of Nutrition, healthy vitamin D levels in mother during pregnancy can positively affect the child’s IQ (Intelligent Quotient). The higher the vitamin D levels, the greater the IQ scores during childhood.
Melanin And Vitamin D Levels
The sunlight consists of two kinds of UV-rays - UVA, and UVB. UVA doesn’t have much of a biological role. Only UVB helps in the synthesis of vitamin D in the skin.
Melanin has photoprotective action - It protects the skin from the harmful effect of ultraviolet radiation. However, higher melanin levels can lead to lower production of vitamin D3.
Darker skin tone is associated with higher levels of melanin.
For light-skinned people, an exposure time from 20-30 min, for two-three times a week, is enough to produce around 20,000 IU of vitamin D3, while for dark-skinned people, the exposure time needs to increase by 2-10 fold to get the same level of vitamin D3.
Black Women Are At A Higher Risk Of Vitamin D Deficiency During Pregnancy
The baby in-utero (in the womb) receives its vitamin D supply for brain development from the pregnant mother.
The melanin production is higher in black women - so there are a higher number of cases of vitamin D deficiency among them.
According to the study, 80% of black pregnant women in the U.S. may have vitamin D deficiency.
Among the study participants, approximately 46% of the mothers were deficient in vitamin D during their pregnancy, and vitamin D levels were lower among black women compared to white women.
Vitamin D And IQ
After controlling several other factors that influence IQ, a study examined the relationship between vitamin D levels in pregnant women and IQ in children.
It was observed that higher vitamin D levels in pregnancy were associated with higher IQ in children ages 4 to 6 years old.
The recommended daily intake of vitamin D is 600 international units (IU). However, on average, Americans consume less than 200 IU in their diet.
In most cases, vitamin D deficiency has an easy fix. Even if it is difficult to get enough sun exposure, vitamin D supplementation is an effective alternative to meet your requirements.
The Takeaways From The Study
- Vitamin D deficiency is widespread, globally, due to reduced exposure to sun and reduced dietary intake.
- Vitamin D deficiency is more commonly found in people of color due to their high melanin levels.
- Vitamin D levels during pregnancy can affect offsprings’ IQ - higher vitamin D levels have been associated with higher IQ scores.
- Vitamin D supplementation is crucial for pregnant women who are at a higher risk for deficiency in order to promote the cognitive function in the offspring.