Everything You Need to Know About Vitamin D
Vitamin D is a vital nutrient for each of us. What sets it apart from other vitamins is its ability to be synthesized through sunlight.
We can obtain vitamin D through food or through the ultraviolet (UV-B) rays of the sun, which synthesize it from our skin.
Although it can be obtained through food or supplements, vitamin D deficiency is one of the most common deficiencies in our country.
Studies on vitamin D have shown a direct correlation with depression and a link between low vitamin D levels and obesity.
Given these reasons, vitamin D deficiency is a significant issue that requires attention. It has even influenced health policies in Scandinavian countries.
When we focus on vitamin D, let's explore what it is, what it does, and how it's used together.
What is Vitamin D?
Vitamin D is absorbed through fats. About 79% of orally ingested vitamin D is absorbed. Vitamin D is stored in the liver.
What sets vitamin D apart from other vitamins is its ability to be synthesized in the skin through sunlight.
Vitamin D synthesis during sun exposure varies depending on the angle of the rays, individuals' skin color, and age. Vitamin D synthesis is lower in the elderly and individuals with darker skin.
What Are the Symptoms of Vitamin D Deficiency?
As mentioned earlier, vitamin D deficiency is so significant that it has influenced health policies. "So, do I have a vitamin D deficiency, what are the symptoms, how will I know?" I hear you asking.
Let's list them;
General body aches, fatigue
Difficulty in losing weight
Difficulty in walking, balance problems
Bone pain, loss of strength
Hair loss
Headache, insomnia
Depression, mood swings
Pain in joints and fingers
Dark circles under the eyes
Excessive sweating or constant coldness
Vitamin D Deficiency - What Does it Do?
Rickets and osteomalacia may occur in vitamin D deficiency.
In addition, let's look at the effects of vitamin D on diseases with studies.
Obesity
Low concentrations of circulating vitamin D are common in obesity. This may represent a potential mechanism explaining the high risk of certain cancers and cardiovascular outcomes.
Vitamin D levels are inversely proportional to BMI (body mass index), waist circumference, and body fat. However, it is positively correlated with age, lean body mass, and vitamin D intake.
Weight loss is associated with increased vitamin D levels among postmenopausal overweight or obese women.
Type II Diabetes
An experiment in non-diabetic subjects over the age of 65 found that those who received 700 IU of vitamin D (plus calcium) had less increase in fasting plasma glucose over 3 years compared to placebo. This means that vitamin D affects blood sugar levels and directly affects diabetes risk.
Depression
A study in Norway with overweight subjects showed significant improvement in depressive symptom scale scores after 1 year among those receiving high doses of vitamin D (20,000 or 40,000 IU per week) compared to placebo.
Fractures and Fall
Vitamin D helps with calcium absorption in the body and plays a role in bone health. In addition, vitamin D is found in rapidly contracting muscle fibers, the first responders during a fall. It is theorized that vitamin D may increase muscle strength and thus prevent falls.
Many studies have shown an association between low vitamin D concentrations and increased fracture and fall risk.
A meta-analysis of 12 fracture prevention trials in older adults found that daily supplementation of approximately 800 IU of vitamin D reduced hip and non-spinal fractures by approximately 20% and that daily supplementation of approximately 400 IU of vitamin D did not provide any benefit.
Researchers at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University examined the best trials of vitamin D and placebo for falls, and concluded that "the reduction in fall risk starts at 700 IU and increases with higher doses.
Age-Related Macular Degeneration
High blood levels of vitamin D appear to be associated with a reduced risk of early age-related macular degeneration (AMD) among women under 75 years of age.
How to Use Vitamin D?
First, let's look at what stages our bodies go through and how it is synthesized. Because there are different types of vitamin D, and we pay close attention to this distinction in its use.
Types of Vitamin D
Vitamin D1 is a molecular compound of lumisterol and ergocalciferol in a 1:1 ratio.
Vitamin D2 (ergocalciferol) is produced by invertebrates, some plants, and fungi. The biological production of D2 is stimulated by ultraviolet light.
Vitamin D3 (cholecalciferol) is synthesized by the reaction of 7-dehydrocholesterol in the skin with UVB radiation from sunlight with an index of three or more. Most of the time, we resort to supplementation for this type.
Vitamin D4 is an analog scientifically known as 22-dihydroergocalciferol.
Vitamin D5 (sitocalciferol) is an analog formed from 7-dehydrositosterol.
So, can we only obtain it through supplementation? What foods contain vitamin D? Let's take a closer look at foods containing vitamin D;
Fatty fish and seafood
Tuna
Salmon
Shrimp
Sardines
Anchovies
Mushrooms
The only vegetarian source of vitamin D.
** It is difficult to meet our vitamin D needs with food alone. Especially in the winter months when we cannot be sufficiently exposed to sunlight, vitamin D supplementation is essential.
While 10-20% of vitamin D is obtained through food and supplements, 80-90% is synthesized through sunlight.
Therefore, sunlight is essential for sufficient levels of vitamin D, and I conclude our article here. Until we meet in my other articles, stay healthy and soak up the sun!
