Vitamin D, also known as the ‘sunshine vitamin’, is majorly produced directly from the sun’s ultraviolet rays while we also get small quantities from foods like raw milk, eggs, mushrooms, cod liver oil, tuna, mackerel and salmon. Vitamin D helps keep our bones and teeth in good condition, aids the proper functioning of the brain and nervous system, reduces the risk of diabetes and helps prevent cancer among its several other benefits.
What is Vitamin d3?
There are five forms of Vitamin D, Vitamins d1, d2, d3, d4 and d5; however vitamins d2 and d3, also known as ergocalciferol and cholecalciferol, are its two major forms. Of these two, Vitamin d3 is the most effective and the easiest for the body to absorb.
Vitamin d3 is directly produced from the sun’s ultraviolet rays by a form of cholesterol found within the skin. The newly produced Vitamin is then transported to the liver and kidneys. The liver converts the cholecalciferol to calcifediol which is in turn further broken down in the kidneys to calcitriol, the biologically usable form of the Vitamin responsible for blood calcium regulation and bone health among others. Vitamin d3 plays an important role in our body’s metabolism, it enhances our immune and neuromuscular functions, it promotes cell growth and also helps reduce inflammation.
We derive more than 90% of our body’s vitamin d3 needs from the sun as studies have ascertained that around 20 minutes of daily sun-skin contact is sufficient to meet the body’s needs. Humans also derive a small amount of Vitamin d3 from food sources like milk, eggs, mushrooms and certain species of fish.
Despite these natural and easy ways of deriving Vitamin d3, many of us are suffering from Vitamin d3 deficiency as we are often indoors all day due to job requirements. This lessens our crucial daily sun-skin exposure time and leaves us with varying degrees of problems related to Vitamin d3 deficiency. Also, the amount of this vitamin which can be produced by your skin is dependent on several factors such as the season and your skin pigmentation.
People living in countries far from the equator, with low sunlight or long winters would definitely have problems enjoying this natural source of the vitamin. Equally, people with darker skin are affected as the higher amount of melanin (a natural protection against the sun’s ultraviolet rays) in their skin prevents it from producing Vitamin d3 as easily as other with less melanin. Therefore, they have to spend more time in the sun to achieve similar levels of the vitamin’s production.
Furthermore, people living in areas with high levels of pollution might have problems getting their vitamin d3 needs from the sun. Sunscreen and excessive clothing could also prevent the sun’s ultraviolet rays from penetrating the skin.
It is equally important to note that the amount of Vitamin d3 obtainable from food is, in most cases, far below the recommended dietary allowance. To meet the required level, people would have to eat an insane amount of food daily which is of course, not feasible.
Due to these problems with its production from the sun and the inadequacy of food sources, several people have rightly resorted to taking supplements to keep their Vitamin d3 levels normal. There are several Vitamin D supplements available today which helps in getting the blood levels of the vitamin to the safe zones.
Are you curious about your body’s vitamin d3 levels? Then you should visit a clinic to carry out the standard test called the 25-hydroxyvitamin D test (blood levels are recorded in nanograms/millilitre (ng/ml)). According to medical sources, the adequate vitamin d3 levels in blood are 30-60 ng/ml.
Vitamin d3 benefits
Vitamin d3 is very important to our body system. It aids the digestive systems and reduces the risk of several diseases. It also helps cure certain health conditions which are directly caused by low Vitamin d3 levels.
Vitamin d3 helps increase the absorption of calcium, magnesium and phosphate into the blood stream by the intestines. Calcium is one of the body’s most important minerals and it is essential for keeping the skeletal system healthy and strong. When the body’s calcium levels begin to decline, the body converts Vitamin d3 into its usable form which is then transported to the intestines and kidneys. In the intestines, the vitamin causes more calcium to be absorbed from digested food while it instructs the kidneys to take out less calcium from the body when making urine.
Vitamin d3 has been proved to strengthen the immune system and aid its proper function. The vitamin also fights diseases such as multiple sclerosis, osteoporosis, heart disease and the flu. Several sources 1 2 3 have equally proved that Vitamin d3 helps lower the risk of cancer by stopping the flow of blood through cancerous cells and tissues which halts their proliferation and causes them to die.
Vitamin d3 is very important to pregnant women as it prevents common diseases such as preeclampsia, diabetes and various bacterial infections. Also, the vitamin improves the health of their babies and lowers the risk of diseases like asthma, eczema etc. among them.
Trying to lose weight? Vitamin d3 might prove to be of great assistance as a recent study 4 proved that taking daily doses of Vitamin d3 and calcium could help suppress appetite and thus lead to an increased rate of weight loss.
Vitamin d3 could also help to suppress anxiety and depression by causing an improvement in the sufferer’s mood stability. According to Dr Al Sears, MD 5, Vitamin D vastly boosts the production of serotonin, the natural mood regulator, in the brain and depression patients recorded a significant improvement in their symptoms when they were placed on a high daily dose of the vitamin
For the elderly, Low Vitamin d3 has been proved to be a risk factor for poor cognitive function. Certain studies 6 7 whose subjects were people of 60 years and above with different forms of cognitive disorders like Alzheimer’s Disease, dementia etc. ascertained that these disorders were related to a low blood level of Vitamin d3. Furthermore, Vitamin d3 has – though not yet conclusively – been found 8 to reduce the risk of mortality among older adults.
As part of its immune strengthening function, proper Vitamin d3 blood levels have been proved 9 10 to reduce the risk of contracting viral diseases such as influenza and even the dreaded HIV/AIDS. Another study 11 also found a link between lower risks of tuberculosis and adequate blood Vitamin D levels. 12
Reduced risk of diabetes is another beneficial effect of Vitamin d3. Vitamin d3 helps to regulate the body’s beta cells which are in charge of insulin production. This regulatory function helps prevent occurrences of inadequate insulin secretion which is the cause of type 1 diabetes.
It is safe to say that the body cannot function properly without Vitamin d3 and a daily supply is necessary to live a healthy life.
Recommended Levels of Vitamin D - You should not followThese National Institute of Health recommended levels of Vitamin D are first and foremost for healthy people in ideal environment. These levels do not take into account your geographical positioning, daily exposure to sun, your skin type or your weight.
|Group||Vitamin D per day|
|Infants 1 - 12 months||400 IU|
|Children 1 - 13 years||600 IU|
|Adults 19 - 70 years||600 IU|
|Seniors 71 +||600 IU|
|Pregnant women||800 IU|
Low Vitamin D
Vitamin D in blood tests resulting in 20 ng/ml or less is considered as inadequate while levels of 12 ng/ml are classified as deficient. As earlier stated, a large and increasing number of people today suffer from Vitamin D deficiency due to reasons such as job demands, poor diet, skin pigmentation etc. Other reasons include regular sunscreen use and completely covering up the skin when outdoors. Obesity has also been tentatively linked to low levels of Vitamin D 13. Unsurprisingly, age is also a factor. The cells of older adults get less Vitamin D from the sun and food with age due to a decrease in Vitamin D receptors 14.
Vitamin D deficiency is a very serious condition with several adverse effects however; the skeletal system is often the most affected parts of the body. Low Vitamin D levels leads to bone diseases such as osteoporosis and rickets. Osteoporosis refers to a condition where the bones become brittle and weak, increasing the risk of fracture from impact. This condition is caused by loss in bone mass and it is quite common among older adults. Rickets, on the other hand, is the softening and weakening of bones among children due to Vitamin D or calcium deficiency. This condition commonly leads to skeletal deformities such as bowed legs or knock knees.
Furthermore, several studies have identified 15 16 that Vitamin D deficiency increases the risk of heart attacks, peripheral arterial disease, strokes, hypertension and heart failure. It hasn’t been ascertained if this vitamin can actually prevent and cure a heart attack but having deficient levels does increase your risk factors of cardiovascular heart disease. Low levels of the ‘sunshine vitamin’ could equally increase your risk of cancer as the vitamin prevents cells from multiplying abnormally in the breast, colon etc.
Severe asthma in children is another direct consequence of Vitamin D deficiency, this time in their mothers. Pregnant women with low Vitamin D levels are at risk of giving birth to infants with this problem as well as others such as eczema and the aforementioned rickets.
Another serious consequence of low Vitamin d levels is multiple sclerosis. Multiple sclerosis affects the brain and the spinal cord and it could also cause permanent nerve damage. Sufferers might lose their motor skills and sight. Other known symptoms of this condition include fatigue, dizziness, tremor, bladder and bowel problems, body pain etc. This chronic neurological disease has no cure and no definite cause as at today. However, a study 17 has proved that Vitamin D deficiency can increase its risk factor by over 40 percent and it commonly affects people from the age range of 15 – 60 years.
Vitamin D is very important to the body and to prevent deficiency, it is advisable to increase the daily sun-skin contact. However, it is also important to keep this action moderate so as to avoid skin problems caused by the sun such as skin cancer and sunburns. Also, a healthier diet based on milk, eggs and fish would go a long way.
However, purchasing Vitamin D supplements is the easiest and best option, especially when kids are involved (you won’t want to sun dry your 2 month old baby in the name of Vitamin D), and this would provide an easy daily supply of the vitamin at economic prices and without any unnecessary stress.
Maximum Vitamin D per day
Just as having too little Vitamin D in the blood is a ticking time bomb, having excess of it could equally be detrimental to health. The issue of the maximum daily intake of Vitamin D is quite complex as this value varies by a number of factors like geographical positioning and most notably weight e.g. A 300 pound person would need much more than the average daily intake of a 100 pound person. Taking this and other factors into account, according to the National Institutes of Health, the upper limits for daily vitamin D intake are 1000 – 1500 IU for infants, 2500 – 3000 IU for children aged 1 to 8 years and 4000 IU for children above 9 years, adults as well as pregnant women. Exceeding these values consistently for a long period of time, e.g. several months, could result in a condition known as Hypervitaminosis D.
For more precise numbers, view the Daily Vitamin D Calculator.
|Group||Vitamin D per day|
|Infants 1 - 12 months||1500 IU|
|Children 1 - 8 years||2500 - 3000 IU|
|Children 9+ years||4000 IU|
|Pregnant women||4000 IU|
Hypervitaminosis D is majorly caused by excessive supplementation rather than excessive exposure to sunlight or diet. The human body helps regulate the amount of Vitamin D derived from sunlight and the amounts gotten from food are small. Hypervitaminosis D is caused by taking excessive daily doses of vitamin D supplements as well as a combined use of the supplements with other drugs containing the vitamin which then adds up to an amount above the recommended daily upper limit. For instance, taking a multivitamin and a separate vitamin D supplement could jointly add up to excessively high levels of Vitamin D and when this is taken for a sufficient period of time, Hypervitaminosis D occurs. Equally, certain high blood pressure and heart medication could cause higher blood Vitamin D levels. Tuberculosis medications as well as certain oestrogen supplements could also result in Hypervitaminosis D.
Hypervitaminosis D commonly leads to hypercalcaemia, which is a condition where there is an excessive build-up of calcium in the body. Hypercalcaemia is a very serious medical condition and its symptoms include vomiting, frequent urination and thirst, constipation, bone pain, kidney stones, weakness, abdominal pain, nausea, insomnia, disorientation, coma, cardiac arrest etc. Untreated hypercalcaemia will cause the body to deposit calcium excessively in the body tissues, such as the arteries, and important organs such as the liver, heart and kidneys and this would most definitely result to organ failure with time.
Pregnant women who develop hypercalcaemia are at risk of having children who are sensitive to Vitamin D and suffer from poor mental abilities and facial misconstructions. Thus, it is very important for a pregnant woman to consult a doctor before taking any Vitamin D supplements.
Other possible effects of Hypervitaminosis D include, weight loss, severe depression, irritability, abnormal heart rhythms, high blood pressure and mental difficulties in kids.
Hypervitaminosis D is simply cured by stopping all Vitamin D supplementation and lowering the patient’s calcium intake. Bisphosphonates and corticosteroids might also be administered to help release excess calcium from the bones.
Nonetheless, it is advisable to prevent this condition from happening at all as it could cause lasting damage to the body. Ensure you are not exceeding the upper limit with your supplements and check your other medications to make sure that they do not contain Vitamin D. Doing regular blood tests about twice a year to analyse your vitamin d levels is always a smart thing to do to keep a track of your health.
- National Cancer Institute.
- The US National Library of Medicine.
- Science Daily.
- Vitamin D Council.
- Dr Al Sears, MD.
- The US National Library of Medicine.
- Practical Neurology.
- The Lancet Diabetes & Endocrinology.
- The US National Library of Medicine.
- Cambridge University Press.
- International Journal of Epidemiology.
- Live Science.
- Vitamin D Wiki.
- Johns Hopkins Medicine.
- Mayo Clinic.