Lack of vitamin D in pregnancy is linked to the development of diseases in adulthood, says study

A lack of vitamin D during pregnancy is linked to the development of a range of diseases in adulthood — from stunted growth to diabetes, obesity and multiple sclerosis. Now, research carried out at FMRP-USP (Faculdade de Medicina de Ribeirão Preto, University of São Paulo) has shown that this nutrient is also essential for the growth and development of muscles throughout life.

Through experiments on mice, the group of scientists concluded that maternal vitamin D deficiency selectively affects the development of type 2 muscle fibers (the so-called white muscle) in male offspring. These fibers atrophied more during the juvenile period (offspring at 21 days). Over the life of the animal, however, they are able to recover and adapt to the deficiency. That’s because the muscle itself is able to produce vitamin D in adult life.

A nutrient obtained through food, but mainly synthesized by the human body after exposure to solar radiation, vitamin D is a hormone that acts on bone health, growth, immunity and metabolism. In the scientific literature there is little data on its effects on muscles.

What intrigued the researchers and will require further study is why the female offspring were protected from the changes induced by maternal deficiency. One hypothesis is that the protection is linked to some hormone, such as estrogen, or something in the placenta.

The work is part of a Thematic Project by Fapesp and was published in the Journal of Cachexia, Sarcopenia and Muscle. It is the result of the doctoral work of the biomedical scientist Natany Garcia Reis.

“The discovery that the muscle of the deficient adult animal is able to compensate for the endogenous deficiency of circulating hormone by increasing its internal production, for me, as a physiologist, is very gratifying because it opens up a huge field of research. physical exercise stimulates this system”, explains Luiz Carlos Navegantes, professor at the Department of Physiology at FMRP-USP and corresponding author of the article.

According to Navegantes, the results obtained bring relevant messages, which reinforce the importance of vitamin D during pregnancy and lactation. “We bring a new clinical look, highlighting the physiological importance of the hormone not only for bones, but also drawing attention to muscle strength”, he adds.

precedent

The FMRP-USP scientists used as one of the starting points for the study the concept that diseases in adult patients can originate in the fetal period.

Female rats were fed a normal diet or a diet without vitamin D for six weeks and then throughout the entire gestation and lactation period. At weaning, male and female pups were separated and fed a standard diet until 180 days of age.

Vitamin D deficiency induced muscle atrophy in male offspring at the end of weaning, an effect that was reversed over time. After 180 days, the fast-twitch (white) skeletal muscles showed a decrease in the number of total fibers, but an increase in fiber size (hypertrophy), while the slow-twitch (red) muscles showed a great loss of muscle strength, with no changes. apparent morphology.

White fiber hypertrophy was associated with higher protein levels of MyoD and myogenin (factors involved in coordinating skeletal muscle development and repair). For unknown reasons, most morphological and biochemical changes were not observed in the skeletal muscle tissue of females.

Navegantes points out that there were studies carried out with pigs showing evidence that maternal vitamin D supplementation promoted muscle growth. “We use this information to advance the research. Now we have students evaluating the effects on the heart, pancreas and other organs. We are also going to analyze how spayed offspring behaves to try to understand the protection for females”, says the professor.

In 2020, another work by the group coordinated by Navegantes and Professor Isis do Carmo Kettelhut, also from FMRP-USP, demonstrated, for the first time, that stimulating the expression of a protein naturally produced by the human body can be a strategy to combat loss of muscle mass. This natural aging process can be intensified in cases of neurodegenerative and inflammatory diseases or in individuals who need to spend long periods in Intensive Care Units (read more at: agencia.fapesp.br/34302/).

The article Maternal vitamin D deficiency affects the morphology and function of glycolytic muscle in adult offspring rats can be read at: https://onlinelibrary.wiley.com/doi/full/10.1002/jcsm.12986.