Large Doses Can Be Harmful Even Without Symptoms Of Toxicity
Large doses of vitamin D can be harmful, even though there may not be immediate symptoms of toxicity.
Vitamin D is very unlikely to cause severe symptoms of toxicity right away, and symptoms may take months or years to show up.
This is one reason why vitamin D toxicity is so difficult to detect.
There have been reports of people taking very large doses of vitamin D for months without symptoms, yet blood tests revealed severe hypercalcemia and symptoms of kidney failure .
The harmful effects of vitamin D are very complex. High doses of vitamin D can cause hypercalcemia without toxicity symptoms, but can also cause toxicity symptoms without hypercalcemia .
To be safe, you should not exceed the 4,000 IU upper limit without consulting with a doctor or dietitian.
Bottom Line:
Vitamin D toxicity usually develops over time, and the harmful effects are very complex. Large doses may cause damage, despite a lack of noticeable symptoms.
How Much Vitamin D To Take
There are few foods containing vitamin D that you can naturally add to your diet. Therefore, you have to resort to dietary supplements to increase the amount of vitamin D in your body.
Nutritionists and scientists have not agreed on an amount of the vitamin that is just enough for the body. What they do agree on is that if you exceed a certain amount of the vitamin, you will experience unpleasant side effects.
They recommend only 1000 IU to babies under the age of six months. Those who are between 7 months and a year old can only tolerate 1500 IU of vitamin D. Toddlers from age 1 to 3 years shouldnt exceed 2500 IU, whereas children from 4 to 8 years should have a maximum of 3000 IU of vitamin D.
From 9 years onwards into adulthood, the highest tolerated intake of vitamin D is 4000 IU. Intake past these recommended amounts will likely result in the undesirable symptoms mentioned above.
Vitamin D is a critical vitamin for the body, and its important to remember that too-low levels can also put you at risk for negative health effects. The best course of action is to get your vitamin D levels tested and talk to your doctor about how to safely increase your vitamin D intake, if necessary.
But Many People Are Deficient In It
For dietary and environmental reasons, large numbers of people are lacking in vitamin Daround 1 billion people worldwide, in fact, according to a 2014 report in the journal Age and Aging. Stateside, 42 percent of Americans are vitamin D deficient, Ohio’s Mercy Medical Center says. And most people are often unaware of their deficiency until they start experiencing health issues as a result, ranging from depression to fatigue to hair loss to muscle pain. And for more health news delivered right to your inbox, .
Also Check: What’s A Good Prenatal Vitamin To Take
What Is Vitamin D Deficiency
Vitamin D deficiency means that you do not have enough vitamin D in your body. Vitamin D is unique because your skin actually produces it by using sunlight. Fair-skinned individuals and those who are younger convert sunshine into vitamin D far better than those who are darker-skinned and over age 50.
Am I Getting Enough Vitamin D
It seems like every time we hear about vitamin D, its because were not getting enough of it. And in fact, its true. Over 40% of Americans dont get enough vitamin D our lifestyles arent what they used to be, and we spend a lot more time indoors.
Worse still, its difficult to find foods that are naturally rich in vitamin D. So, its safe to say that unless we make an effort to get outside and soak up the sun, our chances of getting enough are slim.
Which brings up another notion: When most of us think about getting more, we turn to sunlight. But there must be another way, no?
There is: supplements! Vitamin D supplements are a great way to get your sunshine from the inside-out.
If youre already taking one, be sure to check out our post on when to take vitamin D for maximum efficiency and catching maximum sleep.
So our recommendation? Take your vitamin D during the day with a big, nutritious meal, and get that inner sunshine shining.
You May Like: Where Can You Buy Usana Vitamins
Understanding A Vitamin D Overdose
A vitamin D overdose is when you take in too much vitamin D. But you might be wondering, Can you take too much vitamin D?” Yes, you can. Since theres only so much of the vitamin you can naturally take in from your diet and through your skin, an overdose is likely to be from dietary supplements containing the vitamin.
In areas in the northern hemisphere, there are days when the sun doesnt come out. There are also, of course, people who spend most of the day indoors or sleeping, like office workers and workers on the night shift. These people dont get enough vitamin D through exposure to the suns ultraviolet light.
If youre an adult, the recommended dietary allowance of vitamin D shouldnt exceed 600 international units in one day. More than this can cause vitamin D toxicity and its associated effects in the body.
Does The Intake Of Other Fat
It has been hypothesized that two other fat-soluble vitamins, vitamin K and vitamin A, may play important roles in vitamin D toxicity.
Vitamin K helps regulate where calcium ends up in the body, and high amounts of vitamin D may deplete the bodys stores of vitamin K (
35 ).
Keep in mind that these are just hypotheses, but it may be wise to make sure you are getting enough of these nutrients if you are going to supplement with vitamin D.
Bottom Line:
If you are supplementing with vitamin D, then it may be important to also ensure sufficient intake of vitamin A, vitamin K and magnesium. These may reduce the risk of adverse effects from a higher vitamin D intake.
You May Like: What Can Vitamin D Do For Your Body
What Is Vitamin D
Your skin has the ability to convert sunlight into vitamin D. Every time you step out into the sunlight, your skin is making vitamin D.
But many people also opt for supplements in order to get enough vitamin D. However, by doing this, you risk putting too much of the vitamin into your body. In this article, well look at how much vitamin D is too much. Well also cover the symptoms and side effects of too much vitamin D and what to do when you overdose on the vitamin.
Before we wade into this topic any further, lets first find out what exactly vitamin D is. Vitamin D is a fat-soluble vitamin that plays an integral role in the regulation of calcium and phosphorus in the body and therefore in bone development, as well as muscle and nerve function. It only appears naturally in a few foods, including fatty fish and fish oils. You can also find smaller amounts in egg yolk, beef liver, and cheese.
The most common source of the vitamin is from exposure to sunlight. When you expose your skin to the sun, it begins to make an inert form of the vitamin. Further processing in the liver and the kidney will deliver the final active form of vitamin D, which is what the body needs for various bodily processes.
How Much Vitamin D Is Too Much
Since relatively little is known about how vitamin D toxicity works, it is hard to define an exact threshold for safe or toxic vitamin D intake .
According to the Institute of Medicine, 4000 IU is the safe upper level of daily vitamin D intake. However, doses up to 10,000 IU have not been shown to cause toxicity in healthy individuals (
27 ).
Hypercalcemia caused by regularly taking high amounts of vitamin D supplements may take a few months to resolve. This is because vitamin D accumulates in body fat, and is released into the blood slowly .
Treating vitamin D intoxication includes avoiding sun exposure and eliminating all dietary and supplemental vitamin D.
Your doctor may also correct your calcium levels with increased salt and fluids, often by an intravenous saline.
Bottom Line:
The main consequence of vitamin D toxicity is hypercalcemia, with symptoms including nausea, vomiting, weakness and kidney failure. Treatment involves limiting all vitamin D intake and sun exposure.
You May Like: What Vitamins Should A 60 Year Old Woman Take
What Are The Severe Symptoms Of Vitamin D Toxicity To Watch For
Vitamin D toxicity is rare. It typically only happens if youre taking more than 10,000 IU at one time. You could also be at risk if youve been taking high doses consistently.
Vitamin D toxicity can cause a number of symptoms, but the most common include:
- confusion
In severe cases, excessive Vitamin D can result in life-threatening kidney injury or kidney failure. To treat vitamin D toxicity, a doctor will prescribe intravenous fluids and medications, such as corticosteroids or bisphosphonates.
If youre showing signs of kidney failure, youll be treated with intravenous hydration and medications and in severe cases, dialysis.
How Is A Vitamin D Deficiency Diagnosed
Your doctor can order a blood test to measure your levels of vitamin D. There are two types of tests that might be ordered, but the most common is the 25-hydroxyvitamin D, known as 25D for short. For the blood test, a technician will use a needle to take blood from a vein. You do not need to fast or otherwise prepare for this type of test.
Don’t Miss: What Foods Give You Vitamin B
In Moderation Most Wont Hurt Youand Yes Some Might Help
That being said, Kitchin does believe that a multivitamin can help make up for some deficiencies in a persons diet, especially if they avoid certain food groups like meat or dairy. She also recommends calcium and vitamin D supplements to some of her patients who are at risk of osteoporosis, but I always look at their diet first before prescribing them, she says.
Kitchin takes a daily multivitamin herself, but she actually only takes half a dose . I like to give myself a little extra insurance without overdoing it, she says.
She tells her patients that, if they choose to take a multivitamin, to look for one with no more than 100% of the daily value for any one nutrientand not to spend a lot of money, either. Theres no strong evidence that it will help you, but as long as you keep the dose reasonable, its also not going to hurt you, she says.
Dr. Jenkins agrees that, when taken in moderation, most vitamin and mineral supplements wont cause harm. He also stresses that his recent study only looked at cardiovascular problems and early death, and that supplements may still have benefits in other areas.
We didnt look at overall health, we didnt look at whether people got beautiful hair or skin, or whether your bones got stronger, he says. Im not going to say that some supplements cant be good for you in those ways.
RELATED: 15 Foods That Are High in Vitamin B12
You Can Definitely Take Too Many
But just because supplements are safe in moderation doesnt mean that more is better. Combining multiple supplements or taking higher-than-recommended doses can increase the risk that they can actually cause harm, says Kitchin. Plus, because the industry is not well regulated, there’s no real guarantee that the ingredients and dosage on the label are accurate.
You really cant get toxic doses of nutrients through food, but you can absolutely get toxic doses through supplements, she says.
Taking high doses of vitamin C can lead to stomach cramping and diarrhea, for example. High doses of vitamin A, vitamin D, and other nutrients can lead to more serious, long-term complicationslike liver and kidney problems, or a dangerous hardening of blood vessels.
Weve learned a very important lesson, in that when we isolate these nutrients out of food and put them in super-high doses, we may have some unintended consequences, Kitchin says. Plus, some supplement ingredients, including caffeine powder and red yeast rice, have been shown to be potentially dangerous even in low doses.
Even if none of your supplements individually exceeds the upper limit for a given nutrient, combining several pillslike a multivitamin and an additional vitamin D capsule, for examplemay add up to higher-than-recommended doses. Supplements can also interact with each other, says Kitchin, or with medications youre already taking.
Don’t Miss: What Foods Are High In Zinc And Vitamin C
What Causes Vitamin D Toxicity
Vitamin D toxicity is almost always the result of excess supplementation. Because your body regulates vitamin D production, you are unlikely to develop it as a result of sun exposure . Foods generally do not contain large amounts of vitamin D, so getting an excessive amount in your diet is unlikely.
People may begin taking vitamin D supplements in order to address a deficiency or to help relieve symptoms of things like seasonal affective disorder or depression. The problem is that they may go overboard or think that taking more will produce more beneficial effects.
Supplements: Check The Dose
Chances are, the unfortified foods you eat aren’t a problem. “It’s pretty hard to overdo it from food alone,” says Johanna Dwyer, RD, a senior research scientist with the National Institutes of Health’s Office of Dietary Supplements.
So you’ll want to think about the supplements you take and fortified foods or drinks.
“Most people don’t realize there’s no real advantage to taking more than the recommended amounts of vitamins and minerals, and they don’t recognize there may be disadvantages,” Dwyer says.
“If you’re taking a supplement, stick to one that’s no more than the daily value,” Dwyer says.
Talk with your doctor about any supplements you’re taking, including vitamins and minerals, and the dose you’re taking, too. That way, your doctor can help you keep doses in a safe range.
“If you’re taking a basic multivitamin, there’s no need to fear taking too much,” says Andrew Shao, PhD, senior vice president of scientific and regulatory affairs for the Council for Responsible Nutrition, a trade group for the supplements industry.
“Most multivitamins have such a wide margin of safety that even when you’re combining them with fortified foods, it’s still not going to cause you to keel over,” Shao says.
Continued
Read Also: What Vitamins Cause Weight Loss
How Much Vitamin D Should I Take Per Day
According to Harvard Nutrition Source, we should all be aiming for the Recommended Dietary Allowance of vitamin D. For adults aged over 19 years old, this is 600 IU daily and for adults over the age of 70, its 800 IU daily. But the maximum daily intake unlike to cause harmful effects on the health is 4000 IU, so those lacking in the essential nutrient might consider topping up with vitamins matching this level.
To put this into context, the average IU of standard vitamin D tablets is 1000 IU. This means that whatever the personal recommendation for intake of vitamin D is, a standard vitamin D tablet such as that bought in the supermarket or health food shop, should do the job.
Its not only for immune support that experts recommend vitamin D, however. Vitamin D plays a vital role in calcium absorption and is required for healthy bone and cartilage development and maintenance. It can also help support healthy muscle function and circulation too.LloydsPharmacy pharmacist, Pareena Patel tells us. Its a vitamin which is essential for babies, children, adults and the elderly alike. It is important to take a supplement which has the right intake for the individual. For example, babies should not be taking the same supplement as adults and vice-versa, as too much vitamin D can have a detrimental effect.
What Causes Vitamin D Deficiency
Vitamin D deficiency can be caused by specific medical conditions, such as:
- Cystic fibrosis, Crohn’s disease, and celiac disease: These diseases do not allow the intestines to absorb enough vitamin D through supplements.
- Weight loss surgeries. Weight loss surgeries that reduce the size of the stomach and/or bypasses part of the small intestines make it very difficult to consume sufficient quantities of certain nutrients, vitamins, and minerals. These individuals need to be carefully monitored by their doctors and need to continue to take vitamin D and other supplements throughout their lives.
- Obesity: A body mass index greater than 30 is associated with lower vitamin D levels. Fat cells keep vitamin D isolated so that it is not released. Vitamin D deficiency is more likely in obese people. Obesity often makes it necessary to take larger doses of vitamin D supplements in order to reach and maintain normal D levels.
- Kidney and liver diseases: These diseases reduce the amount of an enzyme needed to change vitamin D to a form that is used in the body. Lack of this enzyme leads to an inadequate level of active vitamin D in the body.
Read Also: What Vitamins Are Good For Acne Prone Skin
Vitamin D Toxicity How Does It Happen
Vitamin D toxicity implies that vitamin D levels in the body are so high that they cause harm.
It is also termed hypervitaminosis D.
Vitamin D is a fat-soluble vitamin. In contrast to water-soluble vitamins, the body has no easy way of getting rid of fat-soluble vitamins.
For this reason, excessive amounts may build up inside the body.
The exact mechanism behind vitamin D toxicity is complicated and isnt fully understood at this point.
However, we know that the active form of vitamin D functions in a similar way as a steroid hormone.
It travels inside cells, telling them to turn genes on or off.
Usually, most of the bodys vitamin D is in storage, bound to either vitamin D receptors or carrier proteins. Very little free vitamin D is available .
However, when vitamin D intake is extreme, the levels can become so high that there isnt any room left on the receptors or carrier proteins.
This may lead to elevated levels of free vitamin D in the body, which may travel inside cells and overwhelm the signalling processes affected by vitamin D.
One of the main signalling processes has to do with increasing the absorption of calcium from the digestive system .
As a result, the main symptom of vitamin D toxicity is hypercalcemia elevated levels of calcium in the blood .
High calcium levels can cause various symptoms, and the calcium can also bind to other tissues and damage them. This includes the kidneys.
It is produced in the skin when it is exposed to sun.
