Would you believe that the majority of the population — between 40 percent and 90 percent or more of adults in the U.S., depending on race — is believed to have a vitamin D deficiency? That’s makes it on the most common nutrient deficiencies.
It’s no wonder that this vitamin is now one of the most recommended supplements by physicians, taken in order to treat and/or prevent vitamin D deficiency symptoms.
People with dark skin, those who live in northern regions of the world where there’s less year-round sun exposure and those who are overweight have an even greater chance of experiencing vitamin D deficiency.
Can vitamin D deficiency be cured? Yes, there are ways you can naturally increase your vitamin D levels and decrease your risk of developing related health conditions.
Spending time in the sun, without sunscreen, is your surest way to get enough. Eating vitamin D-rich foods also helps improve your blood levels.
Read on to understand just how much time you need in the sun and what foods help you avoid vitamin D deficiency.
What Is Vitamin D? (Why We Need It)
Vitamin D is a fat-soluble vitamin that’s stored in the liver and fatty tissues. It’s somewhat different than other vitamins because the body makes most of it on its own (with the help of sunlight), rather than solely relying on food sources to get enough.
Why Do We Need Vitamin D?
Here are some of the benefits associated with vitamin D:
- Contributes to bone health by aiding in calcium absorption into the bones, as well as other vitamins and minerals that contribute to skeletal health, including magnesium, vitamin K and phosphorus.
- Supports the immune system and may help prevent prolonged or excessive inflammatory responses, plus some viruses and infections.
- Can help support healthy cell replication and may play a role in protecting against the development of autoimmune conditions.
- Promotes cardiovascular health and helps regulate blood pressure, cholesterol levels and inflammation.
- Helps manage blood sugar levels and works with calcium to regulate insulin secretion.
- May help prevent depression and mood disorders, especially during the winter.
- Seems to play a role in preventing obesity. Studies show deficiency is tied to greater volumes of fat, serum, liver and muscle mass, although the relationship is still being researched.
Vitamin D Deficiency Symptoms
What happens when your vitamin D is low? According to scientific studies and reviews, the most common vitamin D deficiency symptoms include:
- heart disease and high blood pressure
- autoimmune diseases
- depression and mood disturbances
- poor skin health, including redness, inflammation and dryness
- arthritis and joint pain
- trouble concentrating
- hair loss
- multiple sclerosis
- chronic muscle or bone pain
Causes/Risk Factors/Health Risks
Why do some people develop a deficiency in this vitamin?
It’s believed that one of the biggest reasons that vitamin D deficiency is now a public health problem is because of our modern, primarily indoors lifestyle.
Below is more about the common causes of vitamin D deficiency:
1. Lack of Sun
Most children today spend unprecedented hours inside — watching television, playing video games and surfing the internet. Similarly, most adults work indoors, exercise inside gyms and spend their free time inside their homes where they are sheltered from the sun.
With all this time indoors, it’s no wonder we don’t get enough of the “sunshine vitamin” and that vitamin D deficiency affects over a billion people worldwide.
2. Frequent Use of Sunscreens
As the risk for developing skin cancer has also risen in recent years, doctors strongly encourage the use of sunscreen for children and adults, even through the winter months and when sun exposure is generally limited.
Alarmingly, some research shows that when you wear sunblock SPF 8, you reduce your body’s ability to make vitamin D by 90 percent.
If you choose a sunblock with a higher SPF of 30 (which is the number normally recommended by doctors), you reduce your body’s ability by up to 99 percent. This results in further deficiencies because even though we spend time outdoors, the sunscreen doesn’t allow our bodies to convert vitamin D from the sun.
Other vitamin D deficiency causes and risk factors include:
- Underlying health conditions — Research shows that certain health conditions, such as abdominal obesity, type 2 diabetes, insulin resistance and hypertension, also increases a person’s risk of vitamin D deficiency.
- Having darker skin — According to the National Health and Nutrition Examination Survey, the newest statistics demonstrate that more than 90 percent of people with darker skin pigments (including African-Americans, Hispanics and Asians) living in the United States now suffer from vitamin D insufficiency, while 75 perfect of the white population is deficient.
- Certain occupations — A 2017 study recently revealed that occupation can also play a big role in levels of this vitamin. Researchers found that shift workers, health care workers and indoor workers are at a high risk of developing a deficiency due to reduced outdoor time.
- Being overweight — As the population of overweight and obese adults and children has risen steadily over the past several decades, so has the incidence of vitamin D deficiency symptoms. Sadly, research shows that vitamin D deficiency is correlated with increased risks of developing common cancers, autoimmune diseases, hypertension and various infectious diseases, too.
Is vitamin D deficiency serious?
Public health experts tell us that it can be, and it’s now linked with a growing number of health conditions, such as heart disease, cancer, diabetes and mood-related problems.
Here are some of the potential health risks that may be associated with vitamin D deficiency:
- Weakened bones — A deficiency in vitamin D can result in the softening of your bones, which is called osteomalacia, or a bone abnormality called rickets. Additionally, a deficiency increases your risk for developing osteoporosis and experiencing fractures or broken bones. This is an especially big risk among older adults.
- Susceptibility to infections and viruses — Low levels have been linked with higher incidence of some serious infections, including those that affect the lungs and respiratory system.
- Mood disorders — Because it acts like a hormone within our bodies and affects brain function, vitamin D deficiency has been linked to an increased risk for mood disorders, including depression, seasonal affective disorder and severe mood problems experienced during PMS, insomnia and anxiety.
- Hormone imbalances — Low levels can interfere with proper testosterone levels and estrogen production, leading to imbalances that can result in many unwanted symptoms. Can lack of vitamin D cause weight gain? It’s possible. Some studies show that lower levels may be linked to weight gain in older adults, but the weight gain is usually relatively small. There’s more to learn about this connection, but it’s speculated that this vitamin may affect where fat cells shrink or get bigger.
- Cognitive/mental health problems — Researchers indicate that deficient adults may perform poorer on standardized exams, may have poorer decision-making skills, and may have difficulty with tasks that require focus and attention. Some research has demonstrated a correlation between low levels of vitamin D and an increased risk for developing schizophrenia and multiple sclerosis.
- Susceptibility to some cancers — Vitamin D deficiency symptoms have been correlated with increased risks for cancer development, especially breast, colon and prostate cancers. According to research published in Frontiers in Endocrinology, D vitamin plays a role in factors that influence tumor growth, cell differentiation and apoptosis. Research shows that it can affect the risk of breast, colon and ovarian cancers, possibly due to its role in the cell life cycle or its ability to block excess estrogen.
How can you increase your vitamin D level? While some foods provide vitamin D, exposure to sunlight is still the best way to get the amount you need in order to prevent vitamin D deficiency symptoms.
Importance of Sunlight Exposure:
Most experts recommend getting about 10 to 15 minutes of direct sunlight daily, without wearing sunscreen, if you are fair- to medium-toned. If you have dark skin, you likely need more time outdoors to make enough vitamin D because you naturally have more protection against effects of UV rays.
Some experts recommend that darker-toned people spend about 40 minutes to one hour in the sun daily if possible.
If it’s the winter, you need to double the recommended time to allow enough vitamin D production to occur.
Here is a good rule of thumb to know that your body is making vitamin D:
- You want to look at your shadow and see that it’s shorter than you are. This tells you that the UV index is high enough.
- Between the hours of 10 a.m. to 3 p.m. is usually when the UV index is highest.
If you are worried about not wearing sunscreen and worried about skin cancer, try applying sunscreen to your face and hands but not on your limbs right away (assuming your limbs are exposed). This leaves enough unexposed skin to properly create the vitamin D you need.
Overall, increase your levels naturally through the following practices and foods:
- Sunlight exposure: Aim to spend 10–20 minutes in the sun daily
- Cod liver oil (take about one tablespoon daily)
- Carp fish
- Wild-caught salmon
- Rainbow trout
- Pastured eggs
- Beef liver
- Raw milk
- Fortified milk and dairy products
- Fortified milk alternatives, such as nut-based milks
- Maitake and portobello mushrooms (when exposed to UV light)
How can you raise your vitamin D level quickly? For people who have low levels, vitamin D supplements are available, which come in two forms: D2 and D3.
D3 from animal products (specifically from the cholesterol within these products) is closest to the type humans produce. Vitamin D3 is therefore the more active form and believed to convert much faster than D2.
How Much You Need
The recommended daily allowance for vitamin D, according to the U.S. Department of Agriculture, is 600 to 800 international units per day for adults. However, getting significantly more, around 5,000 IU per day, may be more effective — especially since there is little risk in over-supplementing in most cases.
Keep in mind that this is a general recommendation, and there is no way to know the exact amount that’s best for you without a blood test. You may need a higher or lower amount and should speak to your doctor and learn about vitamin D side effects as well.
Here are more recommendations based on age:
Dosage Recommendation for Children:
- 1–3 years: 600 IU (15 mcg/day)
- 4–8 years: 600 IU (15 mcg/day)
For Older Children and Adults:
- 9–70 years: at least 600 IU (15 mcg/day)
- Older adults over 70 years: 800 IU (20 mcg/day)
- Pregnant and breastfeeding: 600 IU (15 mcg/day)
The only way to know if you are deficient is to have your doctor perform a test, called a 25-hydroxy vitamin D test. This will tell you if, and how severely, you are deficient.
When your doctor performs a blood test and gives you the results for your vitamin D levels, keep these numbers in mind:
- 50+ equals a good level. A 25(OH)D level of >50 nmol/L is now considered the “primary goal.”
- 30–50 means you want to supplement with vitamin D, work on spending more time in the sun and/or add vitamin D foods into your diet.
- Less than 30 means you are very deficient and definitely want to take immediate action to bring those levels up.
When to See Your Doctor
Researchers suggest that anyone with the health conditions below should be tested for vitamin D deficiency, especially if they experience a number of deficiency symptoms described above:
- Ongoing muscle weakness
- Chronic fatigue
- Depression, especially during the winter (which can indicate seasonal depressive disorder)
- Trouble sleeping
- Weak or broken bones
- Weakened immune system
- Inflammation and swelling
- Between 40% and 80% of adults in the U.S. may suffer from vitamin D deficiency symptoms, which can lead to major health issues, such as cardiovascular disease, diabetes, autoimmune disease and cancer.
- Two major causes of vitamin D deficiency symptoms are a lack of sun exposure and the use of sunscreen.
- Sunlight exposure, without sunscreen, for roughly 10 to 20 minutes per day helps your body make about 10,000 units of natural vitamin D.
- What are the symptoms of vitamin d deficiency in adults? The most common include weakness, chronic fatigue, depression, anxiety, trouble sleeping, weak bones and weak immune system.
- Vitamin D deficiency treatment usually involves vitamin D supplementation, ideally D3 (the more active form). Most adults should take between 600 and 5,000 IU daily.