Vitamin D Guide to Deficiency, Signs, and Symptoms

Getting your daily dose of vitamin D isn’t just about increasing sun exposure or about helping to boost the amount of calcium your body absorbs for bones. Vitamin D — from all sources — is used in every single part of the body from your head to your toes, inside and out.

Is it any wonder that you don’t have enough of it when you are using it every minute of every hour, 24/7?

What is Vitamin D?

Unlike vitamins A or C that can easily be found as specific nutrients in food, vitamin D actually refers to a group of natural steroid hormone-like chemicals in the body and plays many roles in the body. In fact, the two main causes of all diseases are closely linked to not having enough vitamin D:

  1. Vitamin D reduces inflammation, and chronic inflammation has been found to be the main culprit of most life-altering conditions including Crohn’s, Alzheimer’s disease, cardiovascular disease, reduced immunity, diabetes, high blood pressure, high cholesterol, Parkinson’s, rheumatoid arthritis, atherosclerosis, and even allergies.
  2. Many of the genes in your body that command your cells to “proliferate and differentiate” — meaning the genes that tell your cells to multiply and grow only when needed and in the right form — are controlled by vitamin D. And the important role of your genes to tell cells when to die is also influenced by vitamin D. When genes don’t do these jobs properly, cancer, Huntington’s disease, heart attack, stroke, atherosclerosis, inflammation, neuromuscular issues, and nervous system disorders can happen.

Of course, vitamin D is also used to treat osteoporosis and bone pain (osteomalacia), especially in people with hyperparathyroidism and osteogenesis imperfecta, an inherited disease in which bones are especially brittle. It also helps prevent fractures in people at risk for osteoporosis, and bone loss (renal osteodystrophy) in people with kidney failure.

And we couldn’t write an article about vitamin D without mentioning its best known and understood job — bringing calcium into bones! Without calcium’s help, all of your bones would be brittle and osteoporotic.

12 Evidence-Based Health Benefits Of Vitamin D

There are many ways that vitamin D works hard to keep you healthy. The following a dozen benefits of vitamin D:

    1. Helps the body absorb calcium, iron, magnesium, and zinc
    2. Reduces bone loss and hip fractures
    3. Prevents cancer, especially breast and colon/colorectal
    4. Reduces Alzheimer’s risk
    5. Decreases cardiovascular disease risk
    6. Reduces high blood pressure
    7. Prevents diabetes
    8. Supports a healthy pregnancy and baby‘s health
    9. Boosts immunity to flu
    10. Prevents autoimmune diseases
    11. Combats depression
    12. Reduces rheumatoid arthritis

For more information on how vitamin D helps these ailments and more benefits of the multitasking vitamin, check out our vitamin D benefits page.

Signs of Vitamin D Deficiency

Early stages of vitamin D deficiency, like many other vitamin deficiencies, often have few obvious signs and symptoms. However, the more common early signs include:

Early signs and symptoms:

    • Muscle weakness or cramps
    • Bone or joint pain
    • Chronic pain
    • Fatigue
    • Excessive sweating
    • Depression
    • High blood pressure
    • Restless sleep
    • Poor concentration
    • Headaches
    • Bladder problems
    • Constipation/diarrhea

Vitamin D deficiency has been shown to play a role in almost every major disease. But the following are the most common advanced signs and symptoms:

10 Causes and Risk Factors for Vitamin D Deficiency

Of course, no one would purposely try to increase their chances of getting any disease. But did you know that you do just that with daily habits that reduce vitamin D? For example, sunscreen blocks not only UV rays, but 95% of vitamin D production.

Look over the following list and consider what lifestyle adjustments you can make to impact your ability to absorb vitamin D. If you find yourself in any of these categories (described in greater detail below), get a blood test through your doctor to determine your vitamin D levels.

1. Sunscreen & Clothing

If you’re wearing sunscreen or covering up with clothing that covers the majority of your skin when you’re out and about in the sun, you’re not making much vitamin D. Sunscreen with SPF 30 can effectively block UVB rays, reducing vitamin D production by 95%, according toThe Journal of Clinical Endocrinology & Metabolism. But sunburns are harmful, so if you have pale skin or burn easily and are lucky enough to live in or travel to a hot climate, it’s ideal to get an hour on bare skin and then lather-up or cover-up for the remainder of your day. In women who cover their skin for religious, cultural or health reasons, softened bones (osteomalacia) has been reported to be higher. This is especially true for pregnant women and babies.

2. Poor Diet

If you were told that you could prevent and even turn around bone loss and osteomalacia by paying attention to its two main culprits, inactivity and poor nutrition, would you make changes? Not eating enough of the foods that naturally include vitamin D, like fish and fish oils, egg yolks, mushrooms, and organ meats, or eating too many refined, processed foods devoid of calcium, magnesium, and other minerals can contribute to a lack of vitamin D. These are dietary choices that can be changed today.

3. Obesity

If you have substantial stores of body fat, you are at greater risk of vitamin D deficiency. This is because once vitamin D is created by the body or taken in a supplement, it is stored in body fat, but it is less bioavailable and usable in larger stores of body fat. A 2013 study also found a possibility that vitamin D may assist in preventing or treating obesity.

4. Aging

Those of us at a certain age are especially at risk of vitamin D deficiency because we are more likely than younger people to stay indoors or use sunscreen. On top of that, elderly people cannot make vitamin D in the skin as effectively as younger people when exposed to the sun. These factors and mobility issues put the home-bound and institutionalized elderly at a very high risk of low vitamin D levels unless supplements are taken.

5. Dark Skin

People with darker skin tend to have lower vitamin D levels than those with light skin. This is because people with more pigmentation in regions including the Middle East, India, Africa, and South America make less vitamin D on exposure to sunlight. And the farther that darker-skinned people move from the equator, the greater the likelihood of vitamin D deficiency. More melanin in the outermost layer of the skin causes a darker complexion, and it is the melanin that reduces the skin’s ability to produce vitamin D.

6. High Blood Pressure

The results of several studies show that vitamin D can reduce high blood pressure — when you have enough of it. These studies suggest that conditions that decrease vitamin D in the skin, like having dark skin while living in northern latitudes, increase hypertension. A 2017 study discovered that for every increase in vitamin D supplementation, and resulting vitamin D increases in the body, systolic blood pressure dropped. In other vitamin D supplementation research, a combination of 1,600 IU/day of vitamin D and 800 mg/day of calcium for eight weeks significantly decreased systolic blood pressure in elderly women compared to calcium alone.

7. Autoimmune Diseases

Arthritis, diabetes mellitus, multiple sclerosis, and rheumatoid arthritis are all autoimmune diseases. Autoimmune diseases occur when the body launches an immune response to its own tissue, rather than foreign bacteria, a virus or malignant cell. Studies are now showing that simple treatment with vitamin D has beneficial effects in all of these diseases. Studies have found that the prevalence of diabetes, multiple sclerosis, and rheumatoid arthritis increases as latitude increases, suggesting that lower exposure to sun and associated decreases in vitamin D, may play a role in developing these diseases.

This is due to the vitamin’s effect on balancing the immune system in general. A 2017 study says this is because it reduces inflammation. Scientists also think that taking vitamin D supplements may decrease the risk of autoimmune diseases.

8. Inflammatory Bowel Diseases

If you suffer from an inflammatory bowel disease like Crohn’s or Ulcerative Colitis, you are probably at increased risk of vitamin D deficiency. This is especially true if you have had small bowel surgery. Unfortunately, this translates into weaker bones.

Children with these digestive issues, especially those affecting the upper gastrointestinal tract, are especially prone to low vitamin D stores. Low levels of this vitamin have been added to poor nutrition, delayed growth, taking corticosteroid drugs, and the inflammatory process itself as factors for low bone mineral density in kids.

9. Kidney Trouble

When you have kidney disease, your kidneys are unable to convert vitamin D into its active form. Difficulties in metabolizing vitamin D play a major role in a malfunctioning parathyroid gland and the hormones it produces, which can cause hyperparathyroidism. The progressive decline in vitamin D in chronic kidney disease is the result of several factors that limit the ability of the failing kidney to maintain the levels of vitamin D. But developing hyperparathyroidism has actually been linked to not taking enough vitamin D in supplements or food, too.

10. Breast-Fed Infants

Controversial as it may sound, infants that are exclusively breastfed are likely to have vitamin D inadequacy. This is because human milk generally provides 25 IU of vitamin D per liter, which is not enough for an infant if it is the sole source of vitamin D. This increases for dark-skinned infants and ones that receive little sun exposure. Older children that are fed foods that don’t naturally contain the vitamin or are not vitamin D fortified are also at risk of vitamin D deficiency.

The American Academy of Pediatrics recommends all infants that are not consuming at least 500 ml (16 ounces) of vitamin D fortified formula or milk be given a vitamin D supplement of 400 IU/day.

Vitamin D Sources

Most of us don’t get enough sunlight year round, not only for our dose of the sunshine vitamin but for our dose of happiness. The sun, at least during spring, summer, and fall, can provide your entire vitamin D requirement. Children and young adults who spend 30 minutes outside two or three times a week will make all the vitamin D they need. But for older people year-round and everyone during the winter, getting your vitamin D from food and supplements is a must.

Where do you live? It has been estimated in latitudes around 40 degrees north or 40 degrees south (Boston is 42 degrees north), there is insufficient UVB radiation available for vitamin D synthesis from November to early March. Ten degrees farther north (Edmonton, Canada) this vitamin D-lacking winter extends from mid-October to mid-March.

When soaking up the sun, it’s important to do it safely as skin cancer can be a real concern. So, how do you get enough sun without risking melanoma? Well, vitamin D activates in your skin in about half the time it takes for skin to burn. So, the amount of time you need to be in the sun is directly related to how dark your skin is. If it takes you 30 minutes of sun exposure to burn, you need around 15 minutes of sun to get your fill of vitamin D. If it takes you four or five hours to burn, you’ll need several hours of sunshine to reach adequate vitamin D levels.

According to 2015 research, adequate vitamin D can be absorbed by a light-skinned individual in as little as 10 minutes of peak sun exposure on arms and legs or face and arms three times weekly. This provides enough vitamin D to allow for storage of any excess for use during the winter.

Of course, eating foods that contain vitamin D every day is an option. Don’t forget that fatty fish, fish oil, organ meats, eggs, and mushrooms all have vitamin D. For more food sources and how much you might need to eat, check the page on The Top Vitamin D Food Sources.

What is the Recommended Intake of Vitamin D?

The RDI, developed by the Institute of Medicine (IOM) of the National Academy of Sciences, is the recommended amount of a nutrient to meet the daily requirements of a healthy individual.

However, the Institute of Medicine determined there was insufficient scientific information to establish an RDI for vitamin D. Instead, the recommended intake is listed as an Adequate Intake (AI), which represents the daily vitamin D intake that should maintain bone health and normal calcium metabolism in healthy people.

Food consumption data suggests intakes of vitamin D, especially for women, are below current recommendations. And many healthcare providers have increased their recommendations for vitamin D supplementation to at least 1,000 IU per day.

Black women are particularly prone to consuming low amounts of vitamin D in their diet. Also, darker-skinned people living north of latitude 37 degrees are even more prone to vitamin D deficiencies because they produce less vitamin D3 than Caucasians in response to usual levels of sun exposure. Therefore, they have lower vitamin D blood concentrations year-round.

In fact, as many as 42% of women of color — compared to just over 4% of white women of childbearing age — have markers of vitamin D deficiency even during the summer!

Daily Adequate Intake (AI) of Vitamin D

The IOM recommends a daily intake of 600 IU for adults up to 50 years of age; 600 IU for adults 51 to 70 years of age; and 800 IU for adults 71 years or older.

Age Children Male Female Pregnancy Lactation

Birth to12 months

400 IU

1 to 13 years

600 IU

14 to 18 years

600 IU

600 IU

600 IU

600 IU

600 IU

19 to 50 years

600 IU

600 IU

600 IU

600 IU

600 IU

51 to 70 year

600 IU

600 IU

71+ years

800 IU

800 IU

How To Test Your Vitamin D and What To Look For

Your doctor can measure your level of 25-hydroxyvitamin D to find out how much vitamin D is active in your body. Your vitamin D level should never be below 30 ng/ml. (Ng means nanograms — one billionth of a gram — per milliliter, which is a standard unit of clinical measurement.) Anything below 20 ng/ml is considered a serious deficiency, which will increase your risk of diseases. In Canada (in the lower latitudes), late winter 25-hydroxyvitamin D levels generally range from 15 to 18 ng/ml, so vitamin deficiency affects a substantial portion of the population.

So adequate amounts of vitamin D are indicated by blood levels of 25(OH)D of at least 30 ng/mL or 75 nmol/L (nanomoles per liter). Optimal levels are 50-80 ng/mL (125-200 nmol/L), depending on which form of measurement- ng/mL or nmol/L- the lab running your blood test uses to report the results.

We recommended you check your vitamin D serum levels twice per year – once in the summer and once in the winter as different seasons may affect your levels. This way, you will discover what level of vitamin D you have circulating in your bloodstream. With this information, you will be able to make an informed decision with your doctor for how much YOU need to supplement to get into a healthy range. Since everyone is different, the amount you may need may differ from someone else. The chart below shows that two people taking the same amount of vitamin D can have different vitamin D levels.

Vitamin D Toxicity

The Canadian Cancer Society set a precedent by recommending Canadian adults supplement daily with 1,000 IU of vitamin D based on scientific research supporting it as a preventative measure against cancer. The American Cancer Society and the Institute of Medicine advise 400–600 IU for most adults and up to 800 IU per day for those over 70 years, based on bone health requirements. But which organization is correct?

According to the American Institute of Medicine’s Food and Nutrition Board, the acceptable highest level of vitamin D to take is 2,000 IU in adults 19 and older. But when the Food and Nutrition Board established this conservative tolerable upper intake level (UL) for vitamin D, studies were limited.

It is very rare to have a vitamin D overdose. Vitamin D toxicity can create abnormally high calcium levels (hypercalcemia). This could result in bone loss, kidney stones, and calcification of organs like the heart and kidneys if untreated over a long period of time. However, the vitamin D that is used by the body is closely regulated and therefore vitamin D toxicity usually only occurs if extreme doses (such as over 10,000 IU) are taken.

Vitamin D toxicity is not caused by too much sun exposure since the body simply doesn’t metabolize or use what it doesn’t need. Overdose will occur at more than one hundred times the recommended daily allowance (roughly one bottle of 90 vitamin D tablets per day) over a period of months. It is apparent then that vitamin D toxicity is unlikely if you take 1,000–2,000 IU daily.

Certain medical conditions can increase the risk of hypercalcemia in response to vitamin D, including primary hyperparathyroidism, sarcoidosis, tuberculosis, and lymphoma. People with these conditions may develop hypercalcemia in response to increased vitamin D (via supplements only) and should consult a healthcare provider first.

Vitamin D Drug Interactions

Several medications can interfere with the way your body metabolizes vitamin D, which can lead to decreased levels.

Click here to see which drug classes interfere with vitamin D. If you take one of these medications, or are unsure about a medication that’s not listed, discuss the topic with your healthcare provider to find a regimen that works for you.

More Vitamin D May Be Better

As mentioned, Adequate Intake levels are constantly being questioned by today’s research. A 2006 study in the American Journal of Public Health, for example, states that an additional 2,600 IU/day of oral vitamin D3 should be given to older women.

Another in theAmerican Journal of Clinical Nutrition had a recommendation of 4,000 IU per day for adults. It seems more studies are warranted on proper vitamin D levels. A 2016 study titled “Vitamin D supplementation: less controversy, more guidance needed” agrees.

A natural source of vitamin D is best and should be combined with calcium and magnesium. AlgaeCal Plus offers 400% of your daily AI of vitamin D3 (1600 IU cholecalciferol per four capsules) in addition to the only plant calcium supplement guaranteed to increase your bone density!

AlgaeCal welcomes new studies on optimal levels of vitamin D. However, research shows you can safely take higher levels of vitamin D3. In fact, more than adequate levels of vitamin D3 may give you extraordinary health benefits. Therefore, we recommend that you get reasonable sun exposure, eat foods rich in vitamin D regularly, and get a vitamin D test twice per year (in the summer and winter) to determine your current vitamin D levels. That way you’ll know your exact needs before you start your supplement program with AlgaeCal Plus.

The two forms of supplemental vitamin D are animal sourced D3 called cholecalciferol (derived from sheep wool’s lanolin), most commonly used in supplements, and chemically produced D2 called ergocalciferol (derived from yeast), which is used in enriched foods such as nut milk and yogurt.

In a 2006 article in the American Journal of Clinical Nutrition, researchers stipulated that vitamin D2, the variety used to fortify some foods, is inferior to vitamin D3. Other research found this to be because vitamin D2 has markedly lower potency and its effects don’t last nearly as long compared to vitamin D3. Check the label on your foods to see whether they have D3, listed as cholecalciferol, or D2, ergocalciferol.

It is also imperative to get enough calcium and magnesium along with vitamin D3 supplementation because the three balance and help the absorption of each other. Research shows D3 supplements are best when combined with calcium and magnesium. The three nutrients work synergistically with each other.

It may be more effective and easier to take a high-quality supplement than to judge how much you are getting — and absorbing — from the fortified foods you eat. AlgaeCal Plus has taken all of this into consideration and not only contains vitamin D3 but also provides the required calcium and magnesium for proper vitamin D absorption and use within the body. It also contains vitamins K2, C, boron and trace minerals — all which have been shown to increase bone density safely and naturally in human clinical trials when taken with Strontium Boost.