Here we’re answering 3 of your most frequently asked vitamin D questions.
Vitamin D is a fat-soluble nutrient, one of the 24 essential micronutrients for the proper functioning of the body. It is proposed by the body naturally when the skin is exposed to the sun, but it is also found naturally in certain foods, such as fish, eggs and dairy products.
This essential vitamin, together with calcium, helps to form bones and maintain the health of the bone system.
Dr Irina Blaga, a paediatric specialist in REGINA MARIA Bratianu Polyclinic from Pitesti, answers the following 3 of the most frequent questions of parents and not only about the role and importance of vitamin D.
1. What is vitamin D?
Also known as calciferol, vitamin D is fat-soluble, water-insoluble, heat-stable and very sensitive to light and oxidants. Unlike other vitamins that are assimilated only through supplements and food, vitamin D is produced in the body when ultraviolet rays come into contact with the skin.
It is responsible for maintaining the normal level of calcium and phosphorus in the body, thus helping the growth and strengthening of bones, especially in children and the elderly.
The vitamin D component includes, as provitamins:
Ergosterol – a substance present in various animal and plant tissues from which vitamin D2 (ergocalciferol) is obtained
7-dehydrocholesterol – a precursor of cholesterol, which through exposure to ultraviolet rays, turns into vitamin D3, natural and animal, called cholecalciferol.
In order to synthesize an adequate amount of vitamin D3, it is necessary to expose the arms, back, face and legs to the sun for 10-15 minutes, 2-3 times a week. The production of vitamin D3 through the skin decreases with age so that, around the age of 70, it is 50% less than at 20 years old.
Hence the need to supplement the intake of vitamin D by consuming food products rich in vitamin D3, including fish oil, fish (salmon, trout, tuna, herring, mackerel), mushrooms, egg yolk and dairy products.
2. Why do we need vitamin D?
Another vitamin D question you all have is why we need vitamin D.
Vitamin D has a role in the assimilation of calcium and phosphorus in the small intestine, as well as in their fixation in bones and teeth, resulting in correct bone mineralization.
Vitamin D brings many benefits to the body:
- It contributes to the good functioning of the thyroid, parathyroid and pituitary gland.
- It prevents the occurrence of rickets, osteoporosis and fractures.
- It ensures a normal neuromuscular function.
- It has a role in regulating the heart rate.
- It is necessary for the proper formation and development of the brain and helps optimal mental functioning throughout life.
- It stimulates the activity of the immune system.
- It enhances the functions that vitamins A and C perform in the body.
- It contributes to the prevention of autoimmune diseases such as rheumatoid arthritis, multiple sclerosis and inflammatory bowel diseases.
The protective role of vitamin D has been the subject of several clinical trials and meta-analyses, which collected data from several studies, but these led to contradictory results.
3. What dose of vitamin D is necessary for children?
The last vitamin D question we answer is about the necessary daily dose of vitamin D for children.
The required dose of vitamin D supplements varies according to age. The American Society of Endocrinology recommends the following daily dose of vitamin D for children, expressed in international units:
• 400 IU for children in the first year of life
• 600 IU for children aged between 1 and 18 years.
Theoretically, a vitamin D supplement should be administered daily throughout the year.