Vitamin D deficiency in young people and adults

Several epidemiological studies have shown that in Italy about 80% of the population shows a Vitamin D deficiency.

Vitamin D, also called the ‘sunshine’ vitamin, is synthesised by our bodies through the absorption of the sun’s rays through our skin. It promotes the absorption of calcium and phosphorus taken in through food, helping to maintain strong bones and teeth. Insufficient vitamin D intake can expose you to osteoporosis, a loss of bone tissue which puts you at risk of fractures.

Especially the elderly and post-menopausal women, but all adults in general, can be subject to vitamin D deficiency if they do not ensure the right levels through proper diet, an outdoor lifestyle and regular exposure to sunlight. Deficiency of this essential substance is linked to skeletal and dental problems. People who suffer from it, whether adults or children, may in fact be subject to other disorders, such as reduced muscle strength and widespread pain. They may also be more prone to infections as vitamin D contributes to the proper functioning of the immune system.


Vitamin D deficiency, or hypovitaminosis D, is defined as low levels of vitamin D in the body. Hypovitaminosis D occurs only when a severe deficiency has been reached. When the deficiency is still slight, only slight complaints are experienced, which are hardly correlated with a vitamin D deficiency, but are more often attributed to fatigue, stress, other dietary deficiencies, etc.

Only when a person reaches a severe deficiency does bone, muscle and joint pain occur. There’s also a general feeling of weakness and the bones begin to show the first signs of fragility. Neurological signs may also appear, such as mental confusion and involuntary muscle contractions, known as muscle cramping disorders.

To understand the reasons that lead to vitamin D deficiency, it’s appropriate to explain how the body obtains this substance.

Vitamin D can be taken in two forms: one is vitamin D2, found in yeasts, algae and some mushrooms; the other is vitamin D3, which can be taken through some foods, but the synthesis of which occurs mainly through exposure of the skin to sunlight (particularly ultraviolet B or UVB rays).

In Italy, the population is frequently subject to low vitamin D levels. The first reason is that, despite the fact that Italy enjoys good solar radiation, adults, children and the elderly spend too little time outdoors, thus not taking advantage of the beneficial effects of the sun’s rays that stimulate vitamin D synthesis in the skin. Exposure of arms and legs to the sun, together with some physical activity such as running, walking or playing in the open air, would be sufficient to provide the body with the necessary amount of this substance, thus avoiding the risk of deficiency.

Another factor that leads to low levels of the precious substance is a diet that includes few foods rich in vitamin D. The main dietary source of vitamin D is cod liver oil, which is not widely available today, but which was once an indispensable restorative to prevent the serious deficiency responsible for rickets in children. Vitamin D is also present in fatty fish, such as tuna and mackerel, in egg yolk, and in dairy products. In some European countries, in order to combat the insufficient intake of vitamin D, this substance is also added to other common foods that naturally lack it or contain a reduced amount, for example foods of plant origin. In Italy, the production of foods fortified with vitamin D is not yet sufficiently widespread, with the exception of some products, for example breakfast cereals.

In adults, in addition to the factors already mentioned, other causes may also lead to a reduction of this substance in the body. In adults, habits such as smoking, alcohol intake and obesity are risk factors for the deficiency of this substance. Some drug therapies can also lead to an increased need for vitamin D, because they prevent the proper intestinal absorption process.

Menopausal women have a greater need for vitamin D intake. The level of oestrogens decreases at this time of life: these hormones play an essential role in calcium and phosphorus absorption for bone health and strength, so more vitamin D is needed to avoid osteoporosis. In the elderly, however, there’s a correlation between a sedentary lifestyle, spent mainly at home, not always adequate nutrition and low levels of vitamin D intake. For these reasons, on the advice of your doctor, you may want to consider using vitamin D supplements.

Even children and young people, the age groups that are most active and should be spending most time outdoors, are not immune from the risk of vitamin D deficiency. This is because of the increased need for vitamin D in these stages of life, when the body is growing and tissues and cells have a greater demand for all nutrients. For this reason, children should spend some time outdoors every day to enjoy the beneficial effects of sunlight.

Children and teens should also not skip common foods that contain vitamin D, such as eggs, fatty fish and dairy products. Vitamin D supplements in these age groups should only be taken on medical advice in cases of non-absorption.

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