As a hormone, it plays several roles in keeping your body’s cells healthy and functioning the way they should.
However, it’s also possible — although rare — for this vitamin to build up and reach toxic levels in the body.
This article discusses six potential side effects of getting excessive amounts of this important vitamin.
Vitamin D is involved in calcium absorption, immune function and protecting bone, muscle and heart health. It occurs naturally in food and can also be produced by your body when your skin is exposed to sunlight.
Yet aside from fatty fish, there are few foods rich in vitamin D. What’s more, most people don’t get enough sun exposure to produce adequate vitamin D.
Because of this, deficiency is very common. In fact, it’s estimated that about 1 billion people worldwide don’t get enough of this vitamin (1).
Supplements are very common, and both vitamin D2 and vitamin D3 can be taken in supplement form. Vitamin D3 is produced in response to sun exposure and is found in animal products, whereas vitamin D2 occurs in plants.
Vitamin D3 has been found to increase blood levels significantly more than D2. Studies have shown that each additional 100 IU of vitamin D3 you consume per day will raise your blood vitamin D levels by 1 ng/ml (2.5 nmol/l), on average (2, 3).
However, taking extremely high doses of vitamin D3 for long periods of time may lead to excessive buildup in the body.
Vitamin D intoxication occurs when blood levels rise above 150 ng/ml (375 nmol/l). Because the vitamin is stored in body fat and released into the bloodstream slowly, the effects of toxicity may last for several months after you stop taking supplements (4).
Importantly, toxicity isn’t common and occurs almost exclusively in people who take long-term, high-dose supplements without monitoring blood levels.
It’s also possible to accidentally consume too much vitamin D by taking supplements that contain much higher amounts than are listed on the label.
Achieving adequate levels of vitamin D in your blood may help boost immunity and protect you from diseases like osteoporosis and cancer (5).
Although a vitamin D level of 30 ng/ml (75 nmol/l) is typically considered adequate, the Vitamin D Council recommends maintaining levels of 40–80 ng/ml (100–200 nmol/l), and states that anything over 100 ng/ml (250 nmol/l) may be harmful (6, 7).
Despite the fact that more people are now taking vitamin D supplements, it’s rare to find someone with very high blood levels of this vitamin.
One recent study looked at data from more than 20,000 people over a 10-year period. It found that only 37 people had levels above 100 ng/ml (250 nmol/l). Only one person had true toxicity, at 364 ng/ml (899 nmol/l) (8).
In one case study, a woman had a level of 476 ng/ml (1,171 nmol/l) after taking a supplement that gave her 186,900 IU of vitamin D3 per day for two months (9).
The woman was admitted to the hospital after she experienced fatigue, forgetfulness, nausea, vomiting, slurred speech and other symptoms (9).
Although only extremely large doses can cause toxicity so rapidly, even strong supporters of these supplements recommend an upper limit of 10,000 IU per day (3).
Vitamin D helps your body absorb calcium from the food you eat. In fact, this is one of its most important roles.
However, if vitamin D intake is excessive, blood calcium may reach levels that cause symptoms that are not only unpleasant, but dangerous.
Symptoms of hypercalcemia, or high blood calcium levels, include:
- Digestive distress, such as vomiting, nausea and stomach pain
- Fatigue, dizziness and confusion
- Excessive thirst
- Frequent urination
In one case study, an older man with dementia who received 50,000 IU of vitamin D daily for six months was repeatedly hospitalized with symptoms related to high calcium levels (10).
In another, two men took improperly labeled vitamin D supplements, leading to blood calcium levels of 13.2–15 mg/dl (3.3–3.7 mmol/l). What’s more, it took a year for their levels to normalize after they stopped taking the supplements (11).
These include nausea, vomiting and poor appetite.
One study followed 10 people who had developed excessive calcium levels after they had taken high-dose vitamin D to correct deficiency.
Similar responses to vitamin D megadoses have been reported in other studies. One woman had nausea and weight loss after taking a supplement from her naturopath that was found to contain 78 times more vitamin D than stated on the label (13, 14).
Importantly, these symptoms occurred in response to extremely high doses of vitamin D3, which led to calcium levels greater than 12 mg/dl (3.0 mmol/l).
Stomach pain, constipation and diarrhea are common digestive complaints that are often related to food intolerances or irritable bowel syndrome.
These symptoms may occur in those receiving high doses of vitamin D to correct deficiency. As with other symptoms, response appears to be individualized even when vitamin D blood levels are similarly elevated.
In one case study, a boy developed stomach pain and constipation after taking improperly labeled vitamin D supplements, whereas his brother experienced elevated blood levels without any other symptoms (16).
In another case study, an 18-month-old child who was given 50,000 IU of vitamin D3 for three months experienced diarrhea, stomach pain and other symptoms. These symptoms resolved after the child stopped taking the supplements (17).
Because vitamin D plays an important role in calcium absorption and bone metabolism, getting enough is crucial for maintaining strong bones.
Although many symptoms of excessive vitamin D are attributed to high blood calcium levels, some researchers suggest that megadoses may lead to low levels of vitamin K2 in the blood (18).
One of vitamin K2’s most important functions is to keep calcium in the bones and out of the blood. It’s believed that very high vitamin D levels may reduce vitamin K2 activity (18, 19).
To protect yourself against bone loss, avoid taking excessive vitamin D supplements and take a vitamin K2 supplement. You can also consume foods rich in vitamin K2, such as grass-fed dairy and meat.
In one case study, a man was hospitalized for kidney failure, elevated blood calcium levels and other symptoms that occurred after he received vitamin D injections prescribed by his doctor (20).
Indeed, most studies have reported moderate-to-severe kidney injury in people who develop vitamin D toxicity.
In one study of 62 people who received excessively high-dose vitamin D injections, each person experienced kidney failure — whether they had healthy kidneys or existing kidney disease (21).
Kidney failure is treated with oral or intravenous hydration and medication.
Vitamin D is extremely important for overall health. Even if you follow a healthy diet, you may require supplements in order to achieve optimal blood levels.
Make sure to avoid excessive doses of vitamin D. Generally speaking, 4,000 IU or less per day is considered safe as long as your blood values are being monitored.
In addition, make sure you purchase supplements from reputable manufacturers to reduce the risk of accidental overdose due to improper labeling.
If you’ve been taking vitamin D supplements and are experiencing any of the symptoms listed in this article, consult a healthcare professional as soon as possible
The world's most expensive countries to live in were calculated by MoveHub, a company dedicated to helping people move abroad, in a new survey. They based their assessment on a range of costs, such as the price of groceries, transport, bills, restaurants and how much renting somewhere to live is. These figures are then compiled into an index, comparing each country to New York, which has an index of 100.
T=20. Ghana — 53.89: Ghana is one of Africa's more prosperous nations, and this is reflected in the cost of living, which is higher than any other African nation, according to MoveHub.
T=20. Italy — 53.89: The cost of living in Italy is higher than in the eurozone's two largest economies, Germany and France.
19. Israel — 54.11: Israel is, comparatively speaking, pretty inexpensive compared to other states in the region like Kuwait and the UAE.
18. Kuwait — 57.31: Kuwait's currency, the Kuwaiti dinar, is one of the strongest currency units in the world, with a single dinar worth £2.63.
17. Japan — 57.62: Japan's economy may have stagnated somewhat in recent years, but it still remains one of the world's powerhouses, and that is reflected in the cost of living.
16. New Zealand — 58.26: As a country that has to import a large proportion of its goods, New Zealand is a pretty expensive place to live.
15. USA — 58.59: New York may be the benchmark for MoveHub's index, but the USA as a whole is a lot cheaper. Living in big cities like New York and Los Angeles may be costly, but in rural areas and smaller cities things are different.
14. Ireland — 59.56: Since the Brexit vote, Ireland has seen a huge surge in passport applications from Brits looking to leave the UK. Should they move across the Irish Sea however, they'll find a country more expensive than their own.
13. Denmark — 60.01: Denmark is the most heavily indebted country in Europe on a personal level, with average household debt equivalent to 265% of incomes, according to Eurostat. That may not be surprising given the cost of living in the country.
12. Australia — 62.39: Like its nearest neighbour New Zealand, much of what is consumed in Australia — besides its big exports such as iron ore — must be imported. This drives up the cost of living significantly.
11. US Virgin Islands — 62.56: The idyllic island nation may look beautiful, but it is a costly place to live, outstripping its parent state, the USA. Costs vary wildly on different islands in the nation, with expat site Expatistan noting that living on the island of St Thomas is much more expensive than the neighbouring Saint Croix.
10. Luxembourg — 64.18: Luxembourg consistently ranks close to the top of lists of the world's wealthiest nations, and it comes close to the top when it comes to the cost of living as well.
9. Qatar — 68.06: The country brings in highly-skilled workers from overseas at extremely competitive salaries, but much of that salary is often cancelled out by the cost of living.
8. United Arab Emirates — 68.39: Famed as a home for the rich and famous, cities in the UAE like Dubai and Abu Dhabi are notoriously expensive.
7. Bahamas — 73.63: The Caribbean state of the Bahamas faces the same problem as many island nations, that imports far outstrip exports, pushing up the price of goods.
6. Norway — 74.47: Scandinavian countries are notoriously expensive, and Norway is no exception. According to Numbeo, the average 1 bedroom apartment in the country costs around £925 per month to rent.
5. Singapore — 76.57: According to the blog Singapore Life News, the average cost of a pint of beer in the city-state is around £8.50.
4. Iceland — 80.47: Cut off from the rest of Europe and with very little fertile ground, Iceland is forced to import much of its food, pushing up costs.
3. Hong Kong — 81.93: Hong Kong is notoriously expensive, and with space at a premium in the incredibly crowded city, apartments are usually both tiny and pricey.
2. Switzerland — 90.68: Switzerland frequently tops lists of the best places on earth to live thanks to great infrastructure, healthcare and a clean environment. However, all this comes at a price and it is the most expensive place in Europe to live.
1. Bermuda — 126.34: The Atlantic Ocean tax haven of Bermuda is officially the most expensive nation on earth, with the country's capital Hamilton also the most expensive individual city on the planet.
As the summer weather continues to get hotter on the planet and more and more people start wearing less and less, it’s high time we learned more about one of the most comfortable inventions that the humankind had ever made – let’s delve into the history and fun facts about SHORTS!
1. In Europe and America during the 19th and the early 20th century ‘short pants’ were worn only by little boys. Mature men would never wear shorts because they wanted to avoid looking childish. Only after World War II, when millions of men served in tropical environments, the perception of shorts as being something immature had changed.
2. Before the World War I ladies could be arrested for driving automobiles without men beside them, as well as for wearing shorts. In the first haf of the 20th century, many American cities were cracking down on shorts. For example, the city of Honesdale, Pa., prohibited wearing them in 1938 because “it is a modest town, not a bathing beach”. This is why girls appearing in shorts could easily cause a car crash back then!
3. It wasn’t until 1932 that tennis star Alice Marble began wearing shorts instead of a skirt on the court. It shocked the tennis world, yet turned shorts into a fashion moment. However, her knee-length bottoms don’t seem too risqué by modern standards.
4. During the 1940s and the early 1950s, pin-up queens, most notably Betty Garble, were responsible for making shorts really short. After becoming a household name, Marilyn Monroe also made a contribution to the popularization of really vampy shorts.
5. One of the loveliest actresses of all times, Audrey Hepburn showed the world that shorts could be an element of a really stylish look. On the set of the classic 1954 movie ‘Sabrina’, she was seen wearing high-waist shorts that left the audience in awe.
6. A British fashion designer Mary Quant is immortalized by the fashion industry as the woman who turned ‘short pants’ into ‘hot pants’. Her super short shorts, along with mini skirts, became a symbol of the Swinging London scene in the mid-1960s and the sexual revolution.
7. The 1970s was the decade that gave the world cut-offs – typically denim shorts, homemade by cutting the trouser legs off. The extreme version of cut-offs were also known as “Daisy Dukes”. It is a reference to a sizzling character from the ‘Dukes of Hazzard’ TV show, played by fabulous Catherine Bach. About ten years ago Jessica Simpson wore her iconic pair of barely-there denim shorts in the ‘Dukes of Hazzard’ remake.
8. In the 1980s, so-called “dolphin shorts” gained huge popularity. This name refers to their side-view that resembles the tail of a dolphin. The gym scene of that era went crazy over this type of shorts.
9. Bright shorts became a sartorial symbol of Bermuda where men wear them as a formal outfit with knee-length socks and a blazer. The origin of this tradition dates back to the early 20th century, when the British military officers found it unbearable to wear long trousers in the hot climate of Bermuda where they were stationed.
10. Many modern types of shorts owe a lot to different athletic activities. Teenagers wear football and basketball shorts all over the globe. Board shorts were originally intended as beachwear and refer to surfboards. Workout or gym shorts offered the maximum level of freedom. That’s why they became popular as casual garments. After Adidas sponsored the 1980 Olympic Games in Moscow, their track shorts turned into a real fashion item for a couple of years.