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.
New research conducted at the University of São Paulo’s Ribeirão Preto School of Medicine (USP) has shown that this nutrient is also critical for lifelong muscle growth and development.
Through experiments with rats, the group of scientists identified that the Maternal vitamin D deficiency selectively affects muscle fiber development type 2 (the so-called white muscle) in male puppies.
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 capable of producing 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.
O study, the result of the doctoral work of biomedical scientist Natany Garcia Reis, was published in the Journal of Cachexia, Sarcopenia and Muscle. The research was supported by the Fundação de Amparo à Pesquisa do Estado de São Paulo (Fapesp).
“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. We can assess, for example, whether physical exercise stimulates this system”, explains Luiz Carlos Navegantes, professor at the USP Department of Physiology 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.
How the analyzes were done
Scientists from the USP School of Medicine used as one of the starting points for the study the concept that diseases in adult patients may 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 musculoskeletal tissue of females.
The researcher 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. We now have students evaluating the effects on the heart, pancreas and other organs. We will also analyze how spayed offspring behave in order 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 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 weight loss muscle.
This natural aging process can be intensified in cases of neurodegenerative and inflammatory diseases or in individuals who need to spend long periods hospitalized in Intensive Care Units.
Source: CNN Brasil
