Low vitamin D level is highly prevalent in humans and is said to be a possible risk factor for various diseases. Here is an insight into the various aspects of this condition.
Deficiency of vitamin D is said to be one of the most underestimated health problems in the world. According to the Vitamin D Council, almost fifty percent of the world population suffers from this condition, which often remains undiagnosed till the symptoms become severe or complications develop. If left untreated for a long time, the condition is said to cause serious complications. Low vitamin D level has long been identified as a risk factor for bone disorders, like rickets.
According to recent studies, deficiency of this vitamin could be a risk factor for some other diseases as well. There are various reports linking vitamin D deficiency to certain types of cancer and diseases, like, multiple sclerosis, heart problems, etc. Symptoms of low vitamin D levels are usually non-specific and are often interpreted as medical conditions, like chronic fatigue syndrome. So the real cause goes unnoticed, till it gives rise to complications, like bone deformities.
Symptoms of Vitamin D Deficiency in Adults
One of the most common low vitamin D symptoms, musculoskeletal pain may worsen during winter. In some cases, this pain is often felt as a deep throbbing sensation in the limbs.
Low vitamin D levels may lead to osteomalacia in adults, who develop weakness and bone pain, especially in ribs, hips, pelvis, thighs and feet. They may find it difficult to walk or climb the stairs. Most of them are found to have an unsteady walking pattern. Such people may also suffer from bone fractures easily.
Mood Swings and Depression
It has been observed that vitamin D deficiency is common in those with depression. Seasonal Affective Disorder (SAD) is a mood disorder that develops during winters, when there is less sunlight. We all know that sunlight exposure is linked to vitamin D production. This vitamin is said to affect the levels of melatonin, a neurotransmitter that plays a major role in regulating moods. With low levels of vitamin D, the body triggers production of melatonin which causes loss of energy, sluggishness and possibly depression.
So, exposure to sunlight produces vitamin D in your body, which in turn reduces the level of melatonin and wards off depression. This is one of the theories that support the view that depression and mood swings are symptoms of low vitamin D levels. In case of women, the changing estrogen level is another factor that is said to be linked to vitamin D deficiency and depression.
Fatigue and Body aches
These symptoms are common for various medical conditions. Those with chronic fatigue syndrome suffer from severe fatigue and exhaustion. Most of them were also detected with low vitamin D levels. Though the symptom is vague, it is common among those with vitamin D deficiency.
Vitamin D deficiency can lead to soft bones that can become porous and brittle. In some people, this condition may cause demineralization of the cochlea, that can eventually lead to hearing loss.
The link between sleep disorders and vitamin D deficiency is supported by the fact that there are numerous vitamin D receptors in those parts of the brain that control normal sleep pattern. It is believed that stabilizing vitamin D levels could be a remedy for sleep problems.
Severe Premenstrual Symptoms
Vitamin D is said to be a remedy for PMS. Though the course of action of the vitamin is not clear in this context, it could be due to its role in boosting calcium levels or activating neurotransmitter function. Vitamin D may also cause hormone fluctuations.
As the immune system gets weaker, there are chances of contracting a number of other diseases, like flu and respiratory infections. With a weak immune system, the overall health can be affected.
Vitamin D is very much important for calcium absorption in the body. This is the reason why low vitamin D level affects dental health. Those with deficiency of this vitamin develop various dental problems, including periodontal disease.
Symptoms of Vitamin D Deficiency in Kids
- Rickets: In children, vitamin D deficiency may cause rickets, which is characterized by soft bones and skull and curved legs. In some cases, the growth rate may also get affected, especially, the height rather than the weight.
- Delay in teething
- Breathing problems
- Recurrent respiratory infection
- Muscle spasms
- Rarely, certain heart problems may also develop
It can be said that the symptoms of low vitamin D levels are vague and can be attributed to a wide range of diseases and disorders. In some cases, the symptoms may not even appear till the vitamin D level drops very low.
Diseases Linked to Low Vitamin D Levels
- High Blood Pressure; Heart Problems
- Multiple Sclerosis; Asthma; Fibromyalgia
- Rheumatoid Arthritis; Chronic Fatigue Syndrome
- Diabetes; Psoriasis; Lupus; Infertility
- Alzheimer’s Disease; Parkinson’s Disease
- Crohn’s Disease; Tuberculosis
- Chronic Lymphocytic Leukemia
- Certain Types of Cancer (breast, prostate, ovarian and colorectal cancer)
Studies regarding the link between vitamin D and these diseases are still underway. It has been suggested that vitamin D regulates the genes that are involved in some of these diseases. Low vitamin D level is also said to be a risk factor for many of them. So, it is inferred that vitamin D supplementation may prove useful for preventing a wide range of diseases and disorders or for relieving their symptoms. So, monitoring the vitamin D level at regular intervals, may prove beneficial.
Vitamin D Blood Test
25-hydroxyvitamin D test [or 25(OH)D test] is said to be the most accurate method for determining the serum concentration of vitamin D. Another method named, 1,25-dihydroxyvitamin D test is not recommended for those who want to detect the possible deficiency of vitamin D. This test is done in those with excess calcium and vitamin D levels (like in sarcoidosis). The normal range of vitamin D is still a much-debated topic. In case of healthy adults, a blood serum concentration of 20 ng/mL is considered ideal by most of the labs in the U.S.
While for some health experts, the low level is below 30 ng/mL, for others it is below 50 ng/mL. For the latter category, the ideal vitamin D level is 50 to 70 ng/mL. So the dosage of vitamin D is decided according to the test result and individual health condition. There is no standard upper limit for vitamin D level. It may range from 50 to 80 ng/mL. In short, there is no universal standard, as far as the range of vitamin D level is concerned. So, it is best to consult an expert physician to analyze your vitamin D level.
Who Are at Risk?
Basically, there are three factors that can lead to a low vitamin D level. One is the inability of the body to produce or use vitamin D. Secondly, some people require extra vitamin D, during certain conditions, which may cause a deficiency. Though food sources of vitamin D are only a few, low dietary intake may also be counted as a reason. The following are some of the common causes for low vitamin D levels.
- A diet that is deficient in vitamin D
- Lack of exposure to sunlight – affects cutaneous production of vitamin D
- Digestive problems – affects absorption of the vitamin
- Kidney and liver diseases – affects metabolism of the vitamin
- Aging – cutaneous production of vitamin diminishes with age
- Women – changing estrogen levels may negatively affect the level of vitamin D
- Pregnant and nursing women – require extra vitamin D
- Use of certain medication, obesity and genetic problems
- Dark skin – melanin affects cutaneous production of vitamin D
Some of the above said causes can be prevented, whereas, others require medical intervention. A basic understanding about vitamin D, its functions in the body and its sources, may prove useful in increasing awareness about this essential nutrient and its deficiency.
Are Vitamin D Supplements Effective?
It is advisable to monitor the vitamin D levels, once in a while. If you are found deficient, your doctor may advise you to take supplements. The dosage of vitamin D supplements may vary according to individual conditions. Though the higher limit is said to be 4000 IU, in some cases higher doses are used for short-term treatment. Vitamin D supplements must be taken under the supervision of a healthcare professional. Exposure to sunlight and dietary intake may also prove beneficial. In some cases, supplements may not prove effective. This may happen in those with certain medical or genetic conditions.
For example, those with celiac disease, Crohn’s disease, etc., vitamin D will not be absorbed properly, no matter how many supplements you take. The same thing happens to those with liver and kidney problems. These organs are responsible for converting vitamin D to its biologically active form. The vitamin D that is made or absorbed by the body is inactive, till it gets activated through hydroxylation that take place in two different organs – kidney and liver.
The liver transforms vitamin D to 25-hydroxyvitamin D or calcidiol, which in turn is converted to 1,25-dihydroxyvitamin D or calcitriol by the kidneys. Deficiency of vitamin K and magnesium may also affect absorption of vitamin D in the body. So, there are various factors that go into determining the level of vitamin D in the body. If supplements fail to boost your vitamin D levels, other factors need to be checked and rectified.
Vitamin D supplements are said to be effective for treating bone loss, osteomalacia, rickets, vitamin D deficiency, psoriasis, hypoparathyroidism, low phosphate level in blood, etc. It may also prove beneficial for those with osteoporosis. Though, there is no conclusive evidence, vitamin D is said to be useful for preventing certain types of cancer, multiple sclerosis, respiratory infection, rheumatoid arthritis, etc. However, these supplements may not be effective for treating high blood pressure, heart disease, diabetes, COPD, asthma or high cholesterol levels.
Avoid vitamin D supplements, if you have kidney and liver diseases, atherosclerosis, certain types of cancer (especially, lymphoma), hyperparathyroidism, sarcoidosis, high blood calcium levels and histoplasmosis.
Vitamin D toxicity
Though it is rare, excess intake of supplements may sometimes cause vitamin D toxicity. This does not happen in case of overexposure to the Sun, as the body has a regulatory mechanism that can check vitamin D production and prevent it from reaching toxic levels. The most common symptoms of vitamin D toxicity are nausea, vomiting, fatigue, constipation and loss of appetite.
How do we Get Vitamin D?
The human body can produce vitamin D, when exposed to the UVB rays of the Sun. It is said that a few minutes of Sun exposure is sufficient for the skin to produce adequate amounts of vitamin D (but, avoid sunburn). So, you need not worry about the side effects of overexposure to Sun. However, there are certain factors that affect the production of vitamin D in the human body, through sunlight exposure.
- Time of the Day: It is believed that midday sunlight (10 am to 2 pm) is best for the skin to produce vitamin D.
- Skin Color: Light-skinned people take less time to synthesize vitamin D from sunlight, whereas those with dark skin require longer duration of sunlight exposure.
- Location: The amount of UVB rays that actually reach the Earth varies with different locations. These rays reach the Earth, when the Sun is above 50 degrees from the horizon.
- Seasonal Changes: The amount of UVB rays that reach the Earth may vary with different seasons and is very low during winters. However, this may also vary with the location.
- Age: Older people (above the age of 40) require longer duration of sunlight exposure for producing vitamin D, as compared to those under the age of 20.
- Use of Sunscreen: Sunlight exposure after applying a sunscreen is of no use, as far as vitamin D synthesis is concerned.
- Skin exposure: As compared to legs and arms that produce only a little amount of vitamin D, exposure of torso is highly beneficial.
- Other factors that can be a hindrance to the production of vitamin D are air pollution, cloudy weather, high altitude, etc.
If sunlight exposure is not possible for any reason, tanning bed can be used as an alternative. In this case too, a few minutes of exposure will be sufficient. However, the cause of concern is the UVA rays emitted by the lamps.
Vitamin D supplements are available as oil (sold in gel capsules or bottles) and water soluble powder (sold as tablets and capsules). Both vitamin D2 and D3 are available as supplements. However, vitamin D3 (the form of vitamin D produced in human body) is preferred, as the body uses it readily. Even the dosage of the supplements must be accurate. The requirement may vary from one person to another, according to the age, health condition, amount of Sun exposure, degree of absorption, etc.
It is said that the vitamin D requirement level recommended by the government authorities (700 IU per day, for those below the age of 70 and 800 IU for those above that age) is far below the actual requirement. According to the Vitamin D Council, the amount of vitamin D required is around 1000 IU for kids below the age of one. Above that age, the requirement is 1000 IU per 25 pounds of body weight.
An average healthy adult requires around 5000 IU of vitamin D, whereas pregnant women and nursing mothers need 6000 IU. According to latest research studies, the vitamin D requirement of an average adult is between 8000 IU to 10,000 IU. As the increase in dosage is still not confirmed by the authorities, it is best to follow the instructions of your doctor, who will decide the dosage as per individual requirement.
Foods With Vitamin D
As mentioned above, there are certain foods that contain vitamin D, but they are not considered adequate to satisfy the daily requirement. Mushrooms and alfalfa contain vitamin D2 in good amounts. The following are some sources of vitamin D3.
- Cod liver oil
- Beef liver
- Goat’s milk
- Ricotta cheese
You may also use foods that are fortified with vitamin D. Another factor that can affect the vitamin D level in the human body is normal metabolism and absorption. For proper absorption of vitamin D, you must have sufficient amount of magnesium, vitamin K and zinc in your body.
Major Functions of Vitamin D
It was during the early years of the twentieth century that researchers found that the disease which affects bone development in children could be prevented by using a compound in cod liver oil. They termed this compound as ‘fat-soluble factor D’, which later came to be known as vitamin D. This vitamin is otherwise known as ‘calciferol’, owing to its ability to boost the quantity of calcium deposits in the bones. Vitamin D is a group of prohormones (a precursor to a hormone), with minimal hormonal effect. The two major forms are vitamin D2 and vitamin D3. The former, which is synthesized by plants is otherwise known as ergocalciferol, and the latter, synthesized by the human body (in the skin, when it is exposed to the ultraviolet rays in the sunlight), is known as cholecalciferol.
► Controls the level of phosphate and calcium in blood
► Regulates bone health
► Invigorates the immune system
► Regulates neuromuscular functions
► Plays a vital role in cardiovascular functions
► Balances blood sugar level and insulin production
► Promotes normal cellular growth
Such supplements are administered in the form of injection, tablets as well as liquid medicine. If the deficiency is caused by any other disease or disorder, treatment should be taken to cure that underlying cause. Dosage of supplements is decided as per individual requirements. However, care must be taken to inform your doctor about your current medical conditions as well as medication.
Disclaimer: This article is for informational purposes only and should not be used as a replacement for expert medical advice. Visiting your physician is the safest way to diagnose and treat any health condition.