Researchers from the National Institute of Health and Medical Research (Inserm) analyzed the medical records of 1,800 French people to understand how adults were filling up with vitamin D and what were the factors influencing its level in the blood.
“This is the first time that a study on the determinants of vitamin D concentration has simultaneously examined so many parameters: sun exposure, phototype (sensitivity of the skin to the sun), dietary intake of vitamin D, socio-demographic data, body size , lifestyle and genetic polymorphisms “, explains Mathilde Touvier, researcher in nutritional epidemiology and co-author of this work.
The French are deficient in vitamin D
The researchers first made an alarming finding. The results of the study reveal that more than half of French people (58%) lack vitamin D, with a concentration of less than 20 nanograms per ml of blood and that 15% are even deficient (less than 10ng / ml): to not be deficient, you should at least have a blood concentration of vitamin D between 30 and 45 ng / ml of blood.
The researchers observed that these deficits were mainly linked to several factors. To sex (being a woman), to age, to lack ofSun exposure, alcohol consumption and a sedentary lifestyle. In contrast, dietary intake of vitamin D did not affect its overall level.
However, vitamin D is essential for health. It allows the fixation of calcium on the bone to consolidate it and would prevent heart disease.
“Among all these factors, some are modifiable”, explains Mathilde Touvier. “It is therefore possible to correct a deficit and prevent it by adopting a healthy lifestyle, regardless of the balance of the diet. In this sense, a light exposure to the sun in everyday life is useful, but be careful, There is no question of exposing yourself to tan. The fact of going out several times a day to go to an appointment or to go shopping improves the status in vitamin D “.
This study confirms figures from the National Institute for Public Health Surveillance (INVS), according to which more than 80% of French people aged 18 to 74 suffer from insufficiency in vitamin D. But supplementation should absolutely not be done without medical advice.
