Vitamin D deficiency is "an epidemic"

Vitamin D deficiency is "an epidemic"


Vitamin D deficiency is "an epidemic"
Currently, vitamin D deficiency is an epidemic, as its prevalence is increasing worldwide. This situation, which can be considered an illness of civilization, has worsened in recent years. Presently, according to data, research and international studies, this condition affects the vast majority of seniors and impacts between 30% and 50% of the general population and is due to profound changes in the demographic pattern, the profile of diseases and the way of life of the majority of people. The most common causes often cited by experts are:
- Reduction of sun exposure
People work less outdoors, children stay more hours in schools and indoors, there is higher rate of institutionalization of the elderly and even changes in clothing, among other things, reduce one’s exposure to the sun.
- Growing use of sunscreens with UVB filters
These are generally used as a preventive measure against skin aging and skin cancer. Sunscreens with an SPF of 10, 20 and 30 reduce, respectively, on average, 90%, 95% and 98% of UVB radiation.
-Increasing situations that alter the absorption, metabolism and bioavailability of vitamin D
These changes are associated with obesity (adipose tissue captures and fixes vitamin D), liver and kidney failure, medication intake, poor gastrointestinal absorption, use of laxatives, among others.
- Ageing Population
This situation spawns a lower capacity for skin synthesis of vitamin D in the elderly.
- Changes in the eating pattern
The intake of more meat and less fish is another cause of vitamin D deficiency
The vitamin that isn’t actually one
To better understand this situation, it is necessary to learn a bit more about vitamin D itself, which belongs to the group of fat-soluble vitamins (dissolves in fat). Straightaway a problem of denomination arises: vitamin D isn’t actually a vitamin, but a steroid hormone, although it continues to be referred to as vitamin for nutritional and public health reasons. By definition, vitamins are metabolism regulating substances, required in small amounts and cannot be produced by our organism.

Since vitamin D can be produced in our skin, through sunlight, it is not technically a vitamin. There are two main chemical forms of vitamin D. One of them is vitamin D2 (ergocalciferol). This vitamin of vegetable origin is obtained through ultraviolet B (UVB) radiation of ergosterol. The second form is vitamin D3 (cholecalciferol), of animal origin, obtained through UVB radiation of 7-dehydrocholesterol.

While UVA rays maintain a constant intensity, ultraviolet B (UVB) varies in intensity throughout the day and year (the higher the sun, the greater the intensity will be) and the weather (it is greater when the hole in the ozone layer is lager and lesser when clouds block the sunlight). On the other hand, the UV radiation (A and B), when in excess, causes sunburn, sun allergies, skin aging and skin cancer. According to the World Health Organization (WHO), UV radiation levels are classified into low (0 to 2), moderate (3 to 5), high (6 and 7), very high (8 to 10) and extreme (11 to 14). The higher the UV index, the higher the cutaneous production of vitamin D will be, but the harmful effects of the sun will also increase.
Going to the beach without sunscreen to absorb more vitamin D
It is necessary that each individual has into account their skin type (the lighter your skin is, the more vitamin D it produces, but it will also get sunburned quicker) and the level of UV radiation they will be exposed to (certain weather reports show the hourly forecast of said level). You should also adopt an appropriate strategy for sun exposure that allows you to benefit from it with minimal risk. Portugal is a sunny country, but not a tropical one, therefore, sun exposure during the winter has little effect in cutaneous production of vitamin D, since the sun isn’t very high.

In order to achieve an adequate production of vitamin D it is necessary, during spring, summer and autumn, between 15 to 30 minutes of unprotected sun exposure (depending on your skin type), at least three to four times a week, during the hours when the UV radiation level is at 4 or 5. A potential strategy is to apply sunscreen only on arrival at the beach and benefit from the minutes that it takes to work to produce vitamin D. Even if, during this period of the year, you produce more vitamin D than is necessary for everyday life, the surplus is stored in the liver and other fatty tissues in the body and can be used later.


Vitamin D can also be obtained from the diet, especially from fatty fish, dairy products, eggs, liver (D3), mushrooms and yeast (D2).Broadly speaking, and in ideal living conditions, between 80% to 90% of vitamin D should originate from skin synthesis (D3) and 10% to 20% from the diet (D2 and D3). However, it is difficult to compensate through food the many deficiencies of the skin production of vitamin D; therefore vitamin D supplements (foods and pills) are often necessary. The most known (and most powerful) supplement is cod liver oil, which now comes in capsules, in order to avoid its unpleasant taste.

Enhancing doses of vitamin D
It is now common practice to supplement food products with vitamin D, namely milk (powder or natural), yogurts, flour and fruit. As for medication, it comes in numerous forms and doses, which may be purchased at pharmacies and other authorized sales outlets, however, you should always consult a healthcare professional (doctor or pharmacist) before taking anything.
Recently, more practical medications were approved, concentrating in single tablet high doses of vitamin D3, allowing for monthly intake plans, which can be a great advantage for the elderly, who generally already take several medications every day. In general, the doses of the supplements and medicines are given in IU (International Units) of Vitamin D, but some products are presented in micrograms. To prevent confusion and dosing errors, use conversion formula: 1 microgram = 40 IU.
The vitamin D metabolism is complex but can be summarized in a simple way. Vitamins D2 and D3 (ergocalciferol and cholecalciferol) are biologically inactive, needing to be processed, first in the liver, into 25-hydroxyvitamin D (calcidiol), and then in the kidney, into 1.25-dihydroxyvitamin D (calcitriol). Calcidiol is the major circulating form, but calcitriol is more biologically potent (it interacts more actively with the nuclear vitamin D receptor, present in most cells of our body). Apart from the kidney, many other organs can produce calcitriol and this local production is responsible for the regulation of about 200 genes.
The biological effects of vitamin D are applied on the phospho-calcium metabolism and promotion of bone formation (prevention of rickets, osteomalacia, osteoporosis and fractures) and include a wide range of other effects, designated as pleiotropic effects, namely an anti-oncogenic action (prevents certain types of cancer), an anti-infective action, an anti-aging action and an anti-inflammatory action (reduces the risk of autoimmune diseases, such as multiple sclerosis, rheumatoid arthritis and inflammatory polyarthritis).

Other biological effects of vitamin D

To those previously mentioned, we can add a cardio-vascular protective effect (reduces the risk of stroke, coronary disease and heart failure), a preventive effect of diabetes mellitus and obesity (improves insulin production and sensitivity), a neuro-protective action (promotes maturation of the central nervous system, improves muscle tone and balance and reduces the risk of falling, cognitive impairment and dementia) and also a protective effect on pregnancy (lower risk of eclampsia and low birth weight).

People with low levels of vitamin D do not benefit from these protections and have a greater risk of suffering from the aforementioned health problems. However, most people with vitamin D deficiency do not have specific complaints, unless this deficiency is highly pronounced and causes heart problems (arrhythmias and heart failure), neurological disorders (tetany and seizures) and changes in bone formation (rickets in children and osteomalacia and osteoporosis in adults).

In most cases, complaints are not specific and include muscle weakness, cramps, sensitivity changes, nonspecific pain, fatigue, lack of balance, higher propensity to infections, falls and fractures, dry skin and brittle nails, among other events. Therefore, it is very important to identify situations of vitamin D deficiency, which makes it necessary to control the vitamin D dosage. The serum level of 25-hydroxyvitamin D (calcidiol) is the best indicator of the body content of vitamin D, reflecting the vitamin obtained from the diet, the cutaneous synthesis and the conversion from the liver deposits.

Its identification is easy and quick, through a blood test, and the results are presented in ng/ml (nanograms per milliliter). There is still no unanimity regarding the correct levels of vitamin D. Some scientific societies consider that values below 12 ng/ml of calcidiol reflect a deficiency, values below 20 ng/ml reflect a need, and values between 30 and 100 ng/ml reflect adequate levels of vitamin D. 


The normal minimum levels of vitamin D


From a technical point of view, the normal minimum levels of vitamin D are those that allow for the optimization of calcium absorption, the preservation of low parathyroid hormone levels and the production of the best benefit to the bone and muscle function, which is achieved with values ranging between 20 and 30 ng/ml, depending on the person. It is exactly to compensate for this variability that you should aim to achieve values greater than 30 ng/ml of 25-hydroxyvitamin D.


On the other hand, the ideal serum levels of vitamin D are those that enable the production of the greater pleiotropic benefits. These levels also vary from one person to another, and should lie between 50 and 80 ng/ml of 25-hydroxyvitamin D. It is not necessary, nor is it feasible, to study the entire population, but it is absolutely necessary to perform screening of vitamin D deficiency in high risk groups, such as the elderly and people who aren’t often exposed to the sun or have darker skin.


The list also includes pregnant and lactating women, postmenopausal women, obese people, individuals with malabsorption syndromes, patients taking medication that interferes with vitamin D, patients with osteoporosis and people with a history of frequent falls and/or pathological fractures. Anyone with low levels of vitamin D (inferior to 30 ng/ml of 25-hydroxyvitamin D) should be treated by a doctor. High doses may be necessary, possibly even thousands of IU per day.


Therapeutic solutions recommended by doctors

You can choose between oral, daily or weekly regimens with vitamin D2 (ergocalciferol) or D3 (cholecalciferol), but the latter is preferable because it ensures higher serum levels in the medium and long-term. Once the desired target values are achieved (greater than 30 ng/ml of 25-hidroxivitamina D), you should have prolonged maintenance therapy regimens, ranging from 400 IU/day for infants and 800 IU/day for seniors. Overweight people, patients taking medication that interferes with vitamin D and individuals with malabsorption syndromes, the therapeutic and maintenance doses of vitamin D should be twice or even three times greater than those used for the general populations.

Although the risk of toxic effects of vitamin D is very low, since it would have to be taken in very high doses for a long time to reach toxic levels, unsupervised self-medication is not advisable, at least in high doses. In conclusion, it can be said that vitamin D deficiency exists and has a high prevalence, but we can also declare that it is easily identifiable and treatable.