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Low Vitamin D Levels in Blood

Low Vitamin D Levels in Blood: Symptoms, Causes, And Treatment

It is important to detect low vitamin D levels in blood as soon as possible, because in the long run, this vitamin D deficiency can conduce to various deleterious conditions like osteomalacia, rickets, heart disease, etc.
Priya Johnson
Last Updated: Mar 14, 2018
According to Michael F. Holick, American translational-physician and scientist, who first identified the major circulating form of vitamin D, believes that almost 1 billion of the world's population, is suffering from vitamin D deficiency and insufficiency. Vitamin D deficiency ranks amongst the first five diseases affecting children.

Vitamin D, the sunshine vitamin is not like the other vitamins we are familiar with. Vitamin D is a fat-soluble vitamin, stored in the fatty tissues of the body. This vitamin is produced by the body, in the presence of sunlight. The liver converts the precursor of vitamin D (7-dehydrocholesterol), which is a form of cholesterol in the skin, to 25-hydroxyvitamin D (calcidiol), in the presence of the Ultraviolet B rays of the sun. This is then converted by the kidneys and other organs, into 1,25 dihydroxyvitamin D or active vitamin D, which is also known as calcitriol.

Vitamin D maintains the level of calcium in the blood (calcium metabolism), thus, is essential for healthy teeth and bones. However, when the level of this vitamin D dips in the body, the body is seen to be affected negatively. Low vitamin D levels in the blood or hypovitaminosis D, is a condition that has been associated with various medical conditions like heart diseases, respiratory illnesses, bone damage, etc.

Causes of Low Vitamin D levels

↪ We've already seen how vitamin D in the skin is synthesized in the presence of sunlight. If the body is not exposed to enough sunlight, the body is unable to synthesize the required amounts of vitamin D.
↪ Besides synthesizing vitamin D from the skin, it can also be obtained from dietary sources. The two prevalent forms of vitamin D; vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol), are found in mushrooms and various types of fish respectively. Inadequate consumption of these foods can also be responsible for vitamin D deficiency. ↪ People with chronic kidney failure may also have vitamin D deficiency.
↪ Defects in the synthesis of vitamin D, can also be another reason for the deficiency.

Checking for Low Vitamin D Levels

It is difficult to detect low vitamin D levels in blood, by just waiting for symptomatic indications. Moreover, it's not possible to carry out treatment for vitamin D deficiency, if one doesn't know its levels are low.

To find out, there is a vitamin D blood test called vitamin D 25 Hydroxy level, or 25-hydroxyvitamin D level blood test. This tests checks for optimal serum 25-hydroxyvitamin D levels, in the blood, which should be around 30.0 to 74.0 nanograms per milliliter (ng/mL).

Below 40 ng/ml is termed as vitamin D insufficiency, while serum levels below 20 ng/ml is termed vitamin D deficiency. However, these standards vary greatly, depending on the health and age of the person. Only if the values drop below 10 ng/ml, rickets and other bone-related disorders are caused. There also exist vitamin D testing kits, by which people can check their vitamin D levels at home itself.

Symptoms of Low Vitamin D Levels in Blood

↪ Since vitamin D is essential for calcium metabolism, lack of adequate amounts causes bone weakening, and other skeletal issues.
↪ The first few symptoms of low vitamin D are bone pain, coupled with joint and muscle aches. This happens because low vitamin D levels result in low calcium absorption from the intestines. When the level of calcium in the blood is low, it draws calcium from the bones and teeth, which in turn results in bone weakening. Dental health is also affected.
↪ The other symptoms are mood swings, depression, fatigue, and general irritability. The person prefers to withdraw from the public eye and prefers to be alone.
↪ People with low vitamin D levels also face sleep issues, and often struggle with insomnia and sleep apnea. This is because the vitamin D receptors in the brain help control sleep patterns, which get disrupted when the levels of vitamin D drop.
↪ In the elderly, a vitamin D deficiency can add to the problems of aging. All skeletal problems, such as bone softening, etc. that naturally occur due to aging, get amplified.
↪ Besides these problems, the elderly also face memory loss issues, low concentration levels, cognitive impairment, and even hearing loss.
↪ Because of the neurological problems associated with low vitamin D levels, it is believed that vitamin D may increase the risk of Alzheimer's disease.

Effects of Low Vitamin D Levels in Blood

When the level of vitamin D in the blood, corresponds to 20 nanograms per milliliter or lower, it is referred to as a vitamin D deficiency. Low levels of vitamin D in the blood for prolonged period of time, may be associated with various health conditions such as:

Osteomalacia and Rickets
Vitamin D plays a prominent role in maintaining skeletal health, as it assists in the absorption of calcium and thereby promotes strong, healthy bones. However, vitamin D deficiency conduces to debilitation of the skeletal structure. The bones become frail, weak and brittle. In children, inadequate levels of vitamin D causes a condition called rickets, while in adults it causes osteomalacia. Low levels of vitamin D in the bloodstream of a pregnant woman can lead to vitamin D deficiency in early infancy. Moreover, nutritional rickets can also occur in breastfeeding babies, because the deficiency passes on from mother to child. There's also an increased risk of osteoporosis later on in life. Growth retardation and skeletal deformities are also some of the problems associated with low vitamin D levels in newborns.

Decline in Overall Cognition
In a study published in July 12, 2010, issue of Archives of Internal Medicine, one of the JAMA/Archives journals, it was said that 'older adults with low levels of vitamin D appear more likely to experience declines in thinking, learning and memory over a six-year period'. Thus, vitamin D deficiency is linked to cognitive decline. Vitamin D deficiency is also believed to be linked to memory loss (dementia).

Triggers Type 2 Diabetes
According to research conducted by the National Institutes of Health (NIH), besides sedentary lifestyle and obesity, vitamin D deficiency plays a major role in triggering type 2 diabetes. They found a distinct link between uncontrollable blood sugar and low levels of vitamin D in blood.

Weight Gain
Research conducted by Erin LeBlanc, an endocrinologist and researcher, at the Kaiser Permanente Center for Health Research in Portland, Ore. revealed that women with lower levels of vitamin D, gained an extra two pounds as compared to those women who had adequate levels of vitamin D in the blood. Although the weight gained is not significantly high, it's food for thought. However, the lack of deeper understanding in this area, prevents us from understanding clearly the link between weight gain and low vitamin D levels.

Multiple Sclerosis
The immune systems of people with multiple sclerosis are seen to attack the myelin sheath of nerve fibers, and appear as lesions on the MRI. Research conducted by Ellen M. Mowry, an assistant professor of neurology at the Johns Hopkins University School of Medicine, found that the lesions in patients with multiple sclerosis were lesser in those with appropriate levels of vitamin D levels, and higher in those with lower levels. However, researcher Mowry also continues to state that there is no evidence proving that appropriate levels of vitamin D in the blood, will help reduce symptoms of multiple sclerosis.

Heart disease, cancer, rheumatoid arthritis, diabetes, hypertension, and depression, are the other effects of low vitamin D levels in the blood.

Who is more prone...

↪ Changes in lifestyle, can be blamed for increasing number of vitamin D deficiencies across the globe. Lack of Sun exposure, due to increased indoor presence, work or technology addiction, can lead to vitamin D deficiency.
↪ People living in places at lower altitudes (above 37 degrees north or below 37 degrees south of the equator), are at greater risk of developing a deficiency.
↪ Those covering most of the body with clothing (Middle East countries), can also have a vitamin D deficiency, due to minimal skin exposure to the Sun.
↪ Wearing sunscreen, before getting out of the house, also hinders vitamin D formation in the skin.
↪ Age is another factor. People above the age of 50, are also prone to lower vitamin D levels, because as the age progresses, the body's ability to synthesize vitamin D, from the Sun reduces, due to lower levels of precursor vitamin D in the skin.
↪ Dark-skinned people are more prone to vitamin D deficiencies, as compared to fair-skinned people. This is because, they take longer time to synthesize the same amount of vitamin D, as compared to fair-skinned people, due to increased melanin content in their skin.

How to Treat Low Vitamin D Levels in Blood

Exposure to the Sun
☼ In order to supply the body with enough vitamin D for the various body requirements, one should expose himself or herself to sunlight for 15-20 minutes, thrice a week.

☼ However, factors such as cloud cover, sunscreen, smog, skin melanin content, etc. can prevent proper synthesis of vitamin D in the body. Thus, these factors need to be kept in mind.

There are a few points to remember while getting exposed to the Sun, for vitamin D synthesis.
1. Make sure you do not apply any sunscreen before sunlight exposure, as it blocks vitamin D synthesis.
2. Avoid exposure to direct rays of the Sun, from about 10:00 a.m. to 3.00 p.m. during the hot summer days.
3. It's best to bask in the rays of the early morning Sun, for vitamin D.
4. Since ultraviolet B rays cannot travel through glass, do not sit in a vehicle or near the window, and think your body is synthesizing vitamin D.

☼ Moreover, the amount of sun exposure will vary from one geographical location to another, the season, skin color, amount of skin exposed, etc.

☼ In winter the amount of sun exposure to the body is lesser, which is why a person will need to be exposed for longer, for adequate synthesis of vitamin D to be carried out in the body.

☼ Moreover, people living in colder regions of the globe will also have to be exposed to sunlight for longer.

☼ Light-skinned people should not spend more than 15 to 20 minutes under the hot Sun, as it will result in sunburn.

☼ Dark-skinned people should receive about 30 to 40 minutes of Sun exposure three times a week, to synthesize adequate amounts of vitamin D in the body. However, increasing sunlight exposure beyond this time will not lead to more vitamin D synthesis, but will only increase the risk of sunburn and skin cancer. The best way to gauge if your skin has had enough sun exposure is to get out of the sun, once your skin turns slightly pink.

Eat Foods High in Vitamin D
There are various kinds of foods containing vitamin D such as fish (herring, mackerel, tuna, sardines, salmon, etc.), eggs, beef liver, mushrooms (Shiitake & Button), cod liver oil, fortified milk, fortified ice-cream, fortified cereals, juices etc. By eating these foods high in vitamin D, one can raise the level of vitamin D in the blood to some extent. Infant formulas also contain vitamin D in them.

Although consuming fish and eggs are dietary sources of vitamin D, one needs to consume them in large quantities every day, so as to obtain the daily recommended value of vitamin D. However, consuming these foods in large quantities can spearhead other problems like high cholesterol levels, etc. Thus, the dietary source of vitamin D is not the most reliable source of vitamin D.

Vitamin D supplements
Since we do not get the required levels of vitamin D, from the diet alone, it is important to take dietary or vitamin D supplements, to help restore the vitamin D levels in the blood. As per the recommendations cited by the Institute of Medicine, 600 IU of vitamin D, is required for an adult on a daily basis.
Age Group RDA (IU)/day Upper Safe Limit/day
Babies (0-12 months) 400 IU 1,000 to 1,500 IU
Infants and Children (1-8 years) 600 IU 2,500 to 3,000 IU
Children and Adults (9-70 years) 600 IU 4,000 IU
> 70 years 800 IU 4,000 IU
Pregnant and Breastfeeding Women 600 IU 4,000 IU

Although the recommended dosage allowance for vitamin D is only 400 IU to 800 IU, various studies reveal that people need much more than the recommended dosage. A minimal dosage of 1,000-2,000 IU, is recommended on a daily basis, for light-skinned people. However, dark-skinned people or people living in areas with less sunlight, can even take a dosage as high as 3000 IU.

It is advised to consume the supplements after the heaviest meal of the day, with maximum fat content, because vitamin D, being a fat-soluble vitamin is absorbed to its best. People get frustrated when they find their vitamin D levels too low, even after taking supplements. Thus, it is important to take the supplement just after the heaviest meal of the day.

Having said all this, it is important to understand that people with kidney disorders, primary hyperthyroidism, granulomatous TB, sarcoidosis should refrain from consuming vitamin D supplements.

One has to be extremely careful while taking these supplements, because there are chances of vitamin D toxicity, which may conduce to vitamin D overdose, such as calcification, urinary stones, kidney stones, muscle weakness, etc. However, to be affected by vitamin D toxicity, one will have to consume more than 50,000 IU of vitamin D supplements a day.

Vitamin D, the sunshine vitamin is very important for the proper functioning of the body, which is why it is important we get our vitamin D levels checked on a regular basis. If supplements are required, take them only after consulting your physician. Self-medication is never advisable, and can spearhead unwanted complications.

Disclaimer: This HealthHearty article is for informative purposes only, and should not be used as a substitute for professional medical advice.