Vitamin D is perceived as the vitamin of the sun. It positively influences the maintenance of calcium-phosphate homeostasis of the body, affects the intestines, kidneys and bones. Moreover, vitamin D regulates the processes of proliferation, differentiation and apoptosis of many cell types. However, very often we face vitamin D deficiency. This deficiency can result in many adverse effects on our health.
What is the level of vitamin D our body should maintain? What can indicate a deficiency and when is it worth considering supplementation? Be sure to check it out!
Why are vitamins so important for our health?
Vitamins are low-molecular organic compounds that, in small amounts, are very needed by our bodies for normal metabolic processes. These are exogenous compounds that enter our bodies with food, but they can also be obtained in synthetic form and supplied to the body in the form of dietary supplements. Vitamins are substances without which it would be impossible for the entire body to work harmoniously. The supply of vitamins externally (with food) is due to the inability of human organisms to produce them on their own. However, there are some exceptions to that rule, and one of them is vitamin D. The main source of vitamin D for our body is dermal synthesis, which occurs with the help of UV radiation.
Vitamins support the immune system, help with proper development or regeneration. Although they occur naturally in food, our diet is not always well balanced, so it sometimes happens that we experience a deficiency of certain vitamins, and our health is getting weakened. When this happens, a change in eating habits may be necessary, and the doctor may additionally order supplementation as well. In order to find out what components our body is lacking, it is a good idea to determine their levels and, based on this, choose the correct vitamin dosage.
Facts and myths about dietary supplements
Talking about dietary supplements, it is worth noting that many misunderstandings have aroused around them. Some people confuse them with drugs, while others consider them dangerous to health. However, the correct use of supplements, according to the manufacturer’s recommendations and the doctor’s guidelines, can bring many benefits.
It is worth to underline that supplements are usually recommended to specific groups, but they can be used by anyone suffering from vitamin and mineral deficiencies. It should also be noted that supplements are not drugs, but food products, even though they are sold in a similar form.
Due to the fact that dietary supplements are not drugs, they do not have healing properties. They can strengthen an organism weakened by deficiencies of certain substances. For dietary supplements to be allowed to enter the market, they must meet certain safety standards. Also, the recommended doses of supplements should not be exceeded, as it may take our health at risk.
How is vitamin D developed and what are its properties?
Vitamin D belongs to the group of fat-soluble vitamins and has very broad biological effects. However, under this name is a group of substances, of which the two most commonly described forms are vitamin D2 and D3. Vitamin D2 (ergocalciferol) is produced by fungi and plants, while D3 (cholecalciferol) is synthesized in the skin. It is also found in foods of animal origin (dietary intake of vitamin D is very often insufficient). However, both of these forms are biologically inactive and must be metabolized. In the liver, vitamin D is converted to calcitriol (25 OH D), the main circulating form of vitamin D. It then reaches the kidneys, where it is converted to 1,25 OH 2D, the active form of vitamin D3.
The properties of vitamin D are very broad. Vitamin D3 can have a beneficial effect on maintaining healthy bones, can prevent osteoporosis, fractures, rickets or osteomalacia. It has an anti-inflammatory effect and can positively influence brain functioning, reduce the risk of depression or neurodegenerative diseases, as well as autoimmune diseases and many others. Its deficiency, on the other hand, leads to unpleasant health consequences.
Vitamin D supplements are available on the market in the form of capsules, drops or tablets. Vitamin D for children usually comes in the form of aerosols or twist-off capsules.
When should we check vitamin D levels?
Vitamin D3 should be tested, among other things, when you suspect vitamin D deficiency or you are struggling with:
- Calcium and phosphorus disorders,
- immune disorders,
- We take medicines for chronic diseases,
- we suffer from malabsorption or digestion, liver disease, kidney disease, nervous system disease, endocrine gland disease, cardiovascular disease, metabolic disease or cancer.
When and how to supplement vitamin D?
Due to the geographic location, residents of Poland have limited opportunities to obtain recommended levels of vitamin D through cutaneous synthesis. This results in the need ofsupplementing deficiencies. We are also not favored by the angle of the sun’s rays, air pollution or cloud cover, and suitable conditions for cutaneous synthesis prevail only half of the year.
So if the blood tests show that concentration of 25 OH D in the plasma is:
- less than 10 ng/ml (25 nmol/l), it could mean that we are suffering from a severe deficiency,
- A result is in the range of 10-20 ng/ml indicates a deficiency,
- The optimal concentration is between 30-50 ng/ml (75-125 nmol/l),
- High concentrations are diagnosed from 75 to 100 ng/ml (187.5-250 nmol/l).
How to treat low vitamin D levels and how to dose vitamin D? When treating vitamin D3 deficiency and aiming for optimal levels, you should be under the constant supervision of a doctor, who, based on the tests, will choose the appropriate dose of vitamin D tailored to the individual needs of our body. Which vitamin D supplement to choose? In order to correctly select a supplement and its dose, it is advisable to consult a specialist and determine the level of vitamin D in blood serum. In Poland, treatment is most often based on the use of cholecalciferol or calcifediol
Daily intake of vitamin D – what dose of vitamin D is safe?
Recommendations for supplementing deficiencies apply to diverse groups of people. the role of the doctor is important here, they should individually determine dosage and implement vitamin D supplementation.
The general recommendations for vitamin D intake for a healthy population are:
- For newborns and infants, 400 IU/day regardless of feeding method,
- For babies born prematurely, 800 IU/day,
- For children from 6 to 12 months of age – 400-600 IU/day,
- For children and adolescents from 1 to 18 years of age 600-2000 IU/day depending on body weight and sun exposure,
- For healthy adults, 800-2000 IU/day, depending on body weight and sun exposure,
- For seniors over 75 years of age, 2000-4000 IU/day,
- For pregnant and breastfeeding women – during pregnancy, it is worthwhile to test vitamin D levels and determine vitamin D dosage based on this. If the determination of 25 OH D levels in the serum is not possible, it is recommended to take vitamin D at a dose of 2000 IU/day, throughout pregnancy, regardless of the season.
For normal-weight patients and for obese ones, the recommended dose of vitamin D may differ. For overweight patients, the doctor may recommend supplementation of cholecalciferol at a higher dose. However, there are recommendations specifying maximum acceptable doses of vitamin D, which should not be exceeded without medical supervision.
Symptoms and causes of vitamin D deficiency
Hypovitaminosis D is favored by obesity, chronic kidney and liver disease, as well as impaired fat absorption and the use of certain drugs. Symptoms of severe vitamin D deficiency include rickets and osteomalacia. Vitamin D deficiency can contribute to an increased risk of low-energy skeletal fractures. People with too low vitamin D levels may also be more susceptible to infections, autoimmune diseases, hypertension, ischemic heart disease, diabetes and certain cancers. In addition, there are also diseases in which malabsorption occurs. These include inflammatory bowel disease, inflammatory bowel disease, short bowel syndrome, as well as visceral disease and cystic fibrosis.
Vitamin D deficiency is also associated with secondary hyperparathyroidism or increased incidence of insulin resistance. In contrast, returning to the25 OH D levels may result in reversal of some of the adverse effects.
It is worth knowing that seniors are predisposed to deficiencies, due to reduced efficiency of skin synthesis, possible malabsorption and altered vitamin D metabolism. On the other hand, too low supply of vitamin D for pregnant womenmay increase the risk of gestational diabetes, pre-eclampsia or premature delivery. For those at risk, it is worthwhile to regularly monitor 25 OH D levels.
Vitamin D overdose – is it possible?
Although the risk of overdose is small, it can occur. Most often, it is caused by improper supplementation.. Exogenous hypervitaminosis can be diagnosed by high 25 OH D levels (above 150 ng/ml), which can be accompanied by severe hypercalcemia and hypercalciuria, as well as very low or even undetectable parathyroid hormone activity.
Remember that our health is influenced by our diet, physical activity and lifestyle, and supplements are only used to supplement certain deficiencies. Taking dietary supplements should be done after prior consultation with a doctor. It is the specialist who should determine the safe dosages for our health. Do not exceed the recommended or maximum supplements daily doses. In addition, current guidelines for vitamin D supplementation and treatment should be followed.