Lack of vitamin D at birth increases the risk of elevated blood pressure in the child

Expecting mothers should pay careful attention to getting enough vitamin D all year round, especially because vitamin D deficiencies are so commonplace, to begin with. Lack of vitamin D at birth and the first years of life is associated with an increased risk of infant hypertension, and the problem can even continue to adulthood. This was shown in a study that is published in the science journal Hypertension. The researchers advise pregnant women to have their vitamin D levels measured, and they even recommend vitamin D supplements for pregnant women and children as a way of preventing elevated blood pressure later in life.

Elevated blood pressure is one of the most chronic and life-threatening diseases worldwide. Many risk factors are involved, including overweight, ageing, type 2 diabetes, smoking etc. An overlooked risk factor is lack of vitamin D, which is becoming increasingly common due to our modern way of living, and it appears that developing fetuses and infants are especially vulnerable.
All cells in the human body have vitamin D receptors. The vitamin is important for our nervous system, brain, calcium uptake, bones, muscles, immune system and for regulating the genes of our cells. Being vitamin D-deficient during pregnancy is not only damaging for the expecting mother’s health, it can also affect the child’s development and health both in the short and long term.

Children’s lack of vitamin D increase their risk of chronically elevated blood pressure

In the new study, scientists from Johns Hopkins University in the USA followed 775 children from Boston Medical Center from birth until their 18th birthday. The majority of children belonged to low-income families, and 68% of the children were African-American.
Low levels of vitamin D were defined as below 11 ng/ml (nanograms per milliliter) in the umbilical cord at birth and below 25 ng/ml in the blood in children during the early stage of childhood.
By comparing these children with children that had adequate vitamin D status the scientists could see that:

• Children that were born with low vitamin D levels were up to 60% more likely to have elevated systolic blood pressure in the ages between 6 and 18 years
• Children with chronically low levels of vitamin D in the early childhood years were twice as likely to have elevated systolic blood pressure in the ages between 3 and 18 years.
• Systolic blood pressure is the top number in the blood pressure reading and refers to the amount of pressure in your arteries during the contraction of your heart muscle
• Elevated systolic blood pressure increases the risk of cardiovascular disease, even if the other blood reading (diastolic blood pressure) is under control

Elevated blood pressure and obesity is a growing problem among children

According to the scientists behind the new study, health authorities at this point do not recommend checking pregnant women and infants for vitamin D deficiency. Nonetheless, their research shows that screening for vitamin D deficiency and using relevant supplements for pregnant women and infants may be an effective way of preventing elevated blood pressure later in life.
One of the main authors, Guoying Wang, PhD, says that the jury is still out on the question about optimal blood levels of vitamin D during pregnancy and early childhood. Therefore, the scientists plan on conducting studies with larger population groups. Not only is childhood hypertension a growing problem, childhood obesity also is. It appears to be a vicious cycle, as research shows that being vitamin D-deficient can in itself increase the risk of overweight.

How do pregnant women and infants make sure to get enough vitamin D?

There is vitamin D in oily fish, cod roe, eggs, and butter, but we only get minimal amounts of the nutrient from our diet. At our latitude, the summer sun is our main source of vitamin D, but many people avoid the sun (due to sun awareness campaigns) or use that much sun factor cream that it interferes with the natural vitamin D synthesis in their skin. Vitamin D supplies in the liver are often that limited that people become vitamin D-deficient during the winter period.
The daily reference intake (RI) level for adults in Denmark is 5 micrograms. The Danish health authorities recommend a 10 micrograms/day supplement of vitamin D to pregnant women, infants, dark-skinned individuals and people that get too little sun exposure. In the United States, adults are advised to get 15 micrograms daily. The different recommendations serve to show that health authorities internationally do not agree when it comes to vitamin D recommendations. Many scientists and experts claim that the actual need for vitamin D may be even higher (that what health authorities recommend), at least for preventing diseases other than osteoporosis.

References:

Guoying Wang et al. Vitamin D Trajectories From Birth to Early Childhood and elevated Systolic Blood Pressure During Childhood and Adolescence. Hypertension 2019

American Heart Association. Low vitamin D at birth raises risk of higher blood pressure in kids. ScienceDaily July 1, 2019

Varshil Mehta and Shivika Aqarwai. Does Vitamin D deficiency Lead to Hypertension? Cureus 2017

Sisley SR et al. Hypothalamic Vitamin D Improves Glucose Homeostasis and Reduces Weight. Diabetes 2016

https://www.sst.dk/da/sundhed-og-livsstil/ernaering/d-vitamin