Vitamin D is an irreplaceable micronutrient that (in combination with other vitamins and minerals) is responsible for your overall health and wellbeing.
However, according to a 2019 Stat Perls study, published in the US National Library of Medicine, 1 billion people worldwide are vitamin D deficient, while about 50% of the world population does not receive sufficient amounts of vitamin D to support their healthy body functions. 
The source Identifies a couple of reasons for such insufficiency:
- Malabsorption of Vitamin D, due to health and organ impairment
- Insufficient vitamin D supply through diet
- Decreased sun exposure (especially in countries with less sun exposure)
This article will guide you through the most common symptoms of Vitamin D deficiency, as well as why do you need this vitamin and how to get proper amounts of it!
Let’s dive in!
Why do you need vitamin D?
Vitamin D is a micronutrient, which is essential for the effective formation of bones and teeth, as well as for keeping them healthy and strong. The reason for this hides in the fact that vitamin D supports the absorption of calcium, which is vital for strong bone structure.  Besides, this micronutrient plays an important role in supporting immune function, nervous system and skin health, as well as other organs, systems, and tissues.
This vitamin is fat-soluble, meaning that it can dissolve it fat and be stored in the body for “later use”. That being said, your body doesn’t need much vitamin D, and yet, deficiency condition is very common.
What are the symptoms of low vitamin D?
The symptoms of vitamin D insufficiency and deficiency may include hypertension, stroke and increased risk of heart attack, depression and low mood, osteoporosis, muscle weakness, and weak immune system. Keep in mind that the severity of those symptoms may vary depending on the severity of the deficiency.
A 2008 medical study published in the Circulation Medical Journal suggests that vitamin D deficiency may be associated to a predisposition for developing high blood pressure (hypertension), as well as related diseases.
Stroke and heart attacks
The same scientific source suggested a possible association between vitamin D deficiency and increased risk of stroke and heart disease (including heart attacks, ischemic heart disease, and heart failure). 
That being said, the study suggests that vitamin D supplementation may have a positive effect on patients suffering from heart disease and hypertension.
A study in the Official Journal of the American Psychosomatic Society suggests that clinical vitamin D deficiency may play a role in the development of anxiety, depression, and other mood-related mental disorders in older adults.
It’s still not proven if young people, or people who live in northern regions (and are exposed to less sun) have the tendency to suffer from more pronounced depression symptoms. However, if you experience unjustified anxiety, overthinking, obsessive thoughts, or other depression-related symptoms, you may want to test your vitamin D blood levels.
As mentioned, vitamin D plays an essential role in the formation of bones and teeth. But what is the relation between vitamin D and bone health in adults?
Evidence suggests that as vitamin D deficiency may lead to malabsorption of calcium, this condition may play a role in the development of bone and joint pain and osteoporosis (especially in older individuals). 
Weak immune system
Evidence suggests that vitamin D may play an important role in immune function (adaptive as well as innate immune responses).  According to the source, vitamin D deficiency can be associated with increased degree of autoimmune responses and reduced immune response to external infections and viruses.
That being said, that patients who catch viruses often or are prone to infection and inflammation are recommended to test their vitamin D levels in order to recognize the reason for their weak immune response.
Who is at risk of vitamin D deficiency?
According to MedlinePlus, the following individuals may be at higher risk of developing vitamin D deficiency :
- Breastfed infants
- Older adults
- IBD or celiac disease patients
- People with dark skin color
- Individuals suffering from obesity
- Osteoporosis patients
- Chronic kidney disease or liver disease patients
How to get enough vitamin D?
The recommended daily amounts of vitamin D may vary across countries, geographic regions, age, sex, and health condition.
However, the general daily dietary allowance for adults, according to the NHS, is 10 micrograms of vitamin D.
YaleMedicine shares some tips that can help you to get enough vitamin D:
- Include it in your diet! Foods like mackerel, salmon, tuna, beef liver, egg yolks, and fortified foods (like milk and yogurt) can help you to incorporate this vitamin in your diet.
- Use supplements (but only under doctors supervision). They can be available in the form of pills or liquid drops. Follow the recommendation of your doctor on use frequency and dosage.
- Go under the sun for 10-20 minutes! But don’t forget to put effective SPF in order to protect your skin from the UV rays. Keep in mind that unprotected sun exposure can lead to increase risk of sunburn and skin cancer.
If you notice some of the symptoms mentioned above, don’t lose time and immediately test yourself. This way, you will spare worries and more serious health conditions. And if the cause for them is insufficient vitamin D, you shall consult your healthcare provider on proper treatment plan!