Vitamin D: Uses, Sources, and Benefits
Vitamin D is one of the most underestimated essential vitamins. Also, it is not basically a vitamin but rather a natural steroid hormone that is derived in a human body from cholesterol, specifically when the skin is exposed to the sun rays. That is why sometimes Vitamin D is called as the “sunshine” vitamin. Having the normal Vitamin D levels is essential for the optimal health.
Vitamin D: definition and types
Being one of the fat-soluble vitamins (like A, D, E, or k), Vitamin D can dissolve in oil or fat and can be accumulated in the body for a long time. According to Healthline, there are 2 main types of Vitamin D:
- Vitamin D3 (also called as cholecalciferol) – that you can find in most animal foods, like egg yolks or fatty fish;
- Vitamin D2 (a.k.a. ergocalciferol) – that can be found only in mushrooms.
Commonly, Vitamin D3 can be the most beneficial for your health, because it was proved to be almost twice as efficient at elevating the Vitamin D levels in blood in the D2 form.
What is Vitamin D good for in your body?
When you consume any sources of Vitamin D, it doesn’t become useful for your body at once. To become active, Vitamin D needs to go through 2 phases:
- It is converted to Calcidiol – the storage form that is located in the liver;
- Then it is converted to Calcitriol, located in the kidney. It is an active steroid hormone that may deliver the health benefits to your body.
For example, the active form of Vitamin D can positively affect the cells related to your bone health – by “telling” the gut cells to absorb phosphorus and calcium. Also, the enough levels of Vitamin D can contribute to the health of your immune system and prevention of certain cancer types. A deficiency of Vitamin D sources in your diet may lead to the critical levels of certain life-essential hormones.
How is a Vitamin D deficiency revealed?
The WebMD experts assure that a lack of Vitamin D is very bad for your health. The major symptoms of the Vitamin D deficiency in adults and children are:
- Aches in bones and muscles;
- Disease of the bones called rickets in kids;
- A general sense of feeling not well;
- Weakness that leads to the difficulty when climbing the stairs or getting up from the floor;
- Stress fractures in pelvis, legs, and hips.
Also, the recent studies claim that people with low vitamin D levels are more prone to heart diseases, diabetes (both type 1 and type 2), dementia, cancer, and autoimmune diseases (for example, multiple sclerosis).
Health care specialists may diagnose a Vitamin D deficiency through simple blood tests and X-rays in order to check your bones. Those people who have a deficiency may additionally take daily Vitamin D capsules (preferably D3 pills) – basically the supplements with the vitamin’s extract. Vitamin D3 capsules can be bought in most health food stores and network supermarkets.
During a blood test, a doctor will measure the Vitamin D storage form – if it is above 20 ng/mL, the levels are normal. The deficiency level of Vit D is any rate under 12 ng/mL.
There are certain risk groups of people more prone to a Vitamin D deficiency. It has been already explained that Vitamin D is one of essential vitamins in a human body. According to Healthline, these risk groups include such people:
- Elderly people;
- Heart attack patients;
- Children in the developing countries;
- People who suffer from osteoporosis.
The recommended Vitamin D dosage
The Recommended Dietary Allowance (RDA) of Vitamin D may vary from infants to adult women and men. In the United States, the RDA for natural Vitamin D is like this:
- Infants (from the birth to 12 months) – 10 mcg (or about 400 international units (IU));
- Children and adults (from 1 to 70 years) – 15 mcg (600 IU);
- Pregnant or lactating women and elderly people above 70 years – 20 mcg (800 IU).
You may consider these rates as the minimal daily doses, while the Institute of Medicine claims that the maximum safe dose is 4000 IU or 100 micrograms.
The sources of Vitamin D: food, drinks and sunshine
Natural Vitamin D can be produced out of cholesterol in your skin that is exposed to the ultraviolet B rays (UVB) from the sun. These rays can provide enough energy required for this reaction to happen.
Many environmental and lifestyle changes may interact with your ability to get enough amounts of Vitamin D through the sunshine. These negative factors are:
- Living in a highly polluted area or big cities where the sunshine is blocked;
- Applying chemical-based sunscreen;
- Spend not enough time outdoors.
That is why it’s essential to consume Vitamin D through other sources than sunlight.
The most common ways of taking Vitamin D is to consume certain foods and drinks. According to Authority-Nutrition.Com, the best-selected foods high in Vitamin D (type D3) are:
- Cod-liver oil – 1 tablespoon – 34 mcg or 1360 IU or 227 % of the daily value;
- Cooked salmon – 3 ounces or 85 g – 11 mcg or 447 IU or 75% of the daily value;
- Canned in water tuna – 3 ounces or 85 g – 4mcg or 154 IU or 26% of the daily value;
- Cooked beef liver – 3 ounces or 85 g – 1 mcg or 42 IU or 7% of the daily value;
- Eggs (but D-vitamin is found only in yolk) – 1 large egg – 1 mcg or 41 IU or 7% of the daily value;
- Canned in oil, drained sardine – 1 sardine – 0.6 mcg or 23 IU or 4% of the daily intake.
Keep in mind that fatty fish is the best sources of Vitamin D are salmon, mackerel, tuna, trout, or swordfish. However, you need to consume this fish daily to get enough of Vitamin D.
That is why doctors recommend for the daily intake another dietary source – fish liver oils, taken once or twice in a single tablespoon.
The potential health benefits of Vitamin D
If you receive enough Vitamin D through natural sources, your body may only get benefits. In particular, Vitamin D can deliver such health benefits:
- The RDA of Vitamin D may prevent the development of osteoporosis and bone fractures in elderly people;
- Taking enough Vitamin can increase your physical strength, particularly, in upper and lower limbs;
- According to a recent study, taking 1100 IU per day of Vit D may prevent cancer (if taken along with enough calcium);
- Vitamin D may provide the mild reduction in the symptom of clinical depression;
- Another study claims that 2000 IU of vitamin D taken daily may reduce the risk of type 1 diabetes by 78%.
The dangers of a D-vitamin overdose
One of the common myths is that you can get overdosed with Vitamin D. However, the possible Vitamin D side effects as well as its toxicity occur very rarely and may only happen if a person took insane large doses for long periods of time.
According to the Mayo Clinic team, that only taking more than 600 IU per day of vitamin D tablets (neither foods nor the sunshine may provide such Vitamin D dosage) during several months may lead to toxicity. The main negative consequence of such Vitamin D toxicity is the accumulation of calcium in your blood (this disorder is called hypercalcemia).
The symptoms of this disorder are poor appetite, vomiting, and nausea. Also, frequent urination, weakness, and other kidney problems may happen. To treat the Vitamin D toxicity, health care specialists can prescribe the intravenous liquids and pills like corticosteroids or bisphosphonates.