Vitamin D is a fat-soluble vitamin and is essential for optimal health.
Only a few foods contain significant amounts of this vitamin. These are oily fish, organ meats and some mushrooms.
Unlike other vitamins that can be obtained through the diet, vitamin D is produced in the body from cholesterol when exposed to sunlight. Most people have a lack of vitamin D, with the exception of residents of countries with a warm sunny climate.
Vitamin D deficiency may be associated with several chronic diseases, including cardiovascular disease and cancer.
Optimal blood levels of vitamin D provide many important health benefits. These benefits will be discussed in this article.
1. Vitamin D Improves Bone Health
It increases the absorption of substances important for bone health – calcium and phosphorus.
Studies show that people with low levels of vitamin D tend to suffer from bone loss. Whereas people taking vitamin D supplements have a 22-33% lower risk of bone fracture.
Vitamin D supplementation improves fracture healing, especially in people with low vitamin D levels.
Most experts agree that people with blood levels of vitamin D up to 25 nmol per liter should take vitamin D at a dosage of 800-1000 IU per day.
In any case, older people who are at increased risk of falls and fractures should follow the above recommendations.
2. Vitamin D Reduces the Risk of Diabetes
In diabetes, the body cannot process carbohydrates normally. There are several types of diabetes, but the most common are type 2 and type 1 diabetes.
Type 1 diabetes is an autoimmune disease with a large genetic component and is usually diagnosed in childhood or adolescence, while type 2 diabetes usually occurs later in life and is closely related to lifestyle.
Vitamin D reduces the risk of both types of diabetes.
Studies show that infants and toddlers who take vitamin D supplements have a 29% to 88% lower risk of developing type 1 diabetes than those who do not.
The recommended daily allowance is 400 IU of vitamin D for infants under one year of age and 600 IU for most children and adults.
Vitamin D protects against type 2 diabetes by reducing insulin resistance, increasing insulin sensitivity, and improving the function of insulin-producing cells.
People with low blood levels of vitamin D can have up to a 55% higher risk of developing type 2 diabetes.
Research evidence suggests that adults who consume at least 500 IU of vitamin D per day have a lower risk of developing type 2 diabetes. Similar results were obtained in relation to vitamin D-deficient children and adolescents.
3. Vitamin D Improves Heart Health
Vitamin D helps improve heart health and reduce the chance of heart attacks.
People with good blood levels of vitamin D have a lower risk of developing heart disease.
Low vitamin D levels significantly increase the chance of developing heart disease. The highest risk has been seen in people with low vitamin D levels who have high blood pressure.
4. Vitamin D reduces the risk of certain types of cancer
Maintaining adequate levels of vitamin D has some benefits in preventing cancer. Various studies point to this.
The risk of developing bladder cancer and the risk of death from this disease is reduced by a quarter.
A number of other studies show that maintaining high levels of vitamin D may reduce the risk of colorectal cancer.
Vitamin D may play a role in slowing the progression of cancer.
5. Vitamin D reduces the risk of premature death
Vitamin D can help you live longer. Several studies describe a surprising consistent relationship between blood levels of vitamin D and the risk of premature death.
Therefore, people living in countries where there is little sun and therefore not getting enough vitamin D should take vitamin D supplements to add a few extra years to their lives.
6. Vitamin D Reduces Symptoms of Depression
Vitamin D may have an effect on depression.
The specific role of the vitamin in the development of depression is not well understood. One theory suggests that it increases the amount of serotonin in the brain, which is a known factor in feelings of well-being and happiness.
One scientific review reports that low vitamin D levels can increase the likelihood of depression by up to 131%.
However, scientific studies to date do not provide definitive evidence that vitamin D is effective in treating depression.
It may depend on the severity of the symptoms. For example, vitamin D appears to be most effective in reducing symptoms in people with severe symptoms of depression, but less effective in those with moderate or mild symptoms.
7. Vitamin D Increases Muscle Strength
Research shows a link between vitamin D and muscle mass and strength gains in both adults and the elderly.
Individuals receiving vitamin D supplements show more muscle mass gains in the upper and lower body than those who did not receive such supplements.
Several studies have examined how vitamin D affects muscle strength, the risk of falls in people, and, accordingly, bone fractures in older people. The results suggest that the supplements improved muscle strength and reduced the risk of falls compared with a placebo (drug without active ingredient) group.
A daily dose of 800-1000 IU appears to be sufficient to cause improvement in the elderly.
It is possible that stronger doses may be required to achieve an increase in muscle strength in young adults.
8. Vitamin D May Help Prevent and Treat Multiple Sclerosis
Studies show that adequate blood levels of vitamin D can help reduce the risk of multiple sclerosis by up to 62%.
People with pre-existing multiple sclerosis and maintaining high blood levels of vitamin D can slow the progression of the disease.
9. Other Vitamin D Benefits
Over the past decade, vitamin D has become a particularly popular topic of scientific research. New research is discovering new and varied benefits of vitamin D, which include:
- Reduction of asthma attacks: daily dose of 300-1200 IU;
- Prevention of colds and viral infections: Vitamin D supplements may help reduce the risk of upper respiratory infections;
- Improving recovery after surgery;
- Reducing chronic pain;
- Having healthy babies: Taking vitamin D during pregnancy helps increase the height and weight of newborns;
- Protection against Parkinson's disease;
- Protection against age-related mental decline;
- Increased blood levels of vitamin D are associated with lower levels of a popular marker of cardiovascular inflammation, C-reactive protein.
Thus, vitamin D plays several important roles in the body. Maintaining sufficient levels by any means available, whether through food, sunbathing, or supplementation, is extremely important for maintaining optimal health and achieving healthy longevity.
Increasing the level of vitamin D by exposure to the sun should be strictly dosed, as this method is fraught with the risk of sunburn and photoaging of the skin. Read more about this in our article "Sunlight causes photoaging of the skin".
It should be noted that "more is better" does not apply to vitamin D. Studies show that benefits in healthy adults are reduced with high doses of the vitamin.
With a blood level of 21 nanograms per milliliter of vitamin D, any additional increase in vitamin D intake was associated with higher levels of C-reactive protein, stiffening of blood vessels, and an increased risk of cardiovascular problems.
Research also points to a link between excess vitamin D and elevated homocysteine levels, another dangerous sign of heart disease.
Excessive intake of vitamin D can damage the kidneys.
Taking high doses of vitamin D for a long time can lead to excessive accumulation in the body. Vitamin D toxicity occurs when blood levels rise above 150 ng/mL (375 nmol per liter). Since vitamin D is stored in adipose tissue and released into the bloodstream slowly, the effects of intoxication can last several months after supplementation is stopped.
About the possible dosages of taking vitamin D, you should consult your doctor.