The Possible Link Between Vitamin D And Chronic Conditions
Generally, research on the role vitamin D may play in disease prevention and management is murky. Particularly with regard to the benefits of taking supplements, most of the studies have been observational or done on small groups . Until recent years, there has been a lack of large randomized, controlled trials, which are the gold standard for medical research because such studies point to cause-and-effect relationships between factors. The data now coming in from such trials fails to back up previous claims about the benefits of vitamin D supplementation.
But one thing is for sure: The scientific communitys interest in vitamin D clearly isnt waning. Heres what some of the latest research suggests about how the vitamin may affect certain chronic conditions.
Bone Health As mentioned, vitamin D helps in the absorption of calcium in the gut. So its no surprise that vitamin D supplements have long been recommended for preserving bone health. However, recent research has found that they dont live up to the hype. A review of more than 81 clinical trials published in November 2018 in TheLancet Diabetes and Endocrinology found that vitamin D supplements dont prevent fractures or falls, or affect bone mineral density to a degree that is clinically meaningful.
You Can Generally Get Your Daily Dose Of Vitamin D From The Sun But There Are Exceptions
Though the exact amount of time you need to spend in the sun varies, it is possible for your body to create its daily allotment of vitamin D when exposed to direct sunlight.
First, your skin tone makes a difference: People with lighter skin tones need 10 to 15 minutes of direct sun exposure each day.
Clines said that people with darker skin tones need a little more time to get their vitamin D allotment because the melanin in the skin competes with vitamin D synthesis. The amount of time people with darker skin tones need in the sun depends on how much melanin is in the skin, but studies show people with darker skin need roughly 25 minutes in the sun. Some experts say upward of 30 minutes is necessary.
Additionally, sunscreen at SPF 30 or higher, tinted car windows and plexiglass all block vitamin D synthesis in the skin, Clines said. Sfeir pointed out that your arms and legs must be bare to reap the suns vitamin D benefits fully. Also, cloudy days block the suns rays and therefore your ability to synthesize vitamin D.
Both experts stressed that its important to remember that sun exposure can lead to skin cancer, so if you are at heightened risk for the disease you should find other ways to get the nutrient.
Recommended Daily Intake Of Vitamin D
The recommended daily intake of vitamin D is only 600 IU. Only elderly people need a higher daily dosage of 800 IU.
On the other hand, the Endocrinology Society estimated that this dosage may not be enough for people who dont have adequate sun exposure. Hence, they recommend a daily vitamin D intake of 1,5002,200 IU, in order, to maintain adequate vitamin D levels.
In any case, a daily dosage up to 4,000 IU is considered pretty safe.
Above all, you should check your blood levels concentrations of vitamin D3 regularly. Ideally, you should have vitamin D3 concentrations of 50 nmol/L or 20 ng/mL. If you have less, you may benefit from taking vitamin D supplements.
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Which Nutrients Are Required To Be Listed On The Nutrition And Supplement Facts Labels
The Nutrition Facts label must list total fat, saturated fat, trans fat, cholesterol, sodium, total carbohydrate, dietary fiber, total sugars, added sugars, protein, and certain vitamins and minerals. While the actual amount and %DV of vitamin D, calcium, iron, and potassium must be listed, other vitamins and minerals may be listed voluntarily by the manufacturer.
However, they are required to list any vitamins and minerals that are added to the food or if a statement is made on the package labeling about their health effects or the amount contained in the food .
Similarly, the Supplement Facts label is required to list the same nutrients as the Nutrition Facts label when any of these nutrients are found in the supplement in an amount considered to be greater than zero. For more information see 21 CFR 101.9.
Use %DV to determine if a serving of the food is high or low in an individual nutrient. As a general guide:
- 5% DV or less of a nutrient per serving is considered low.
- 20% DV or more of a nutrient per serving is considered high.
More often, choose foods that are:
- Higher in dietary fiber, vitamin D, calcium, iron, and potassium.
- Lower in saturated fat, sodium, and added sugars.
How Much Vitamin D Do You Need
Despite widespread assertions in the popular and scientific press that many Americans have a vitamin D deficiency, the term “deficiency” isn’t strictly accurate. The official definition of a vitamin deficiency means that specific health problems stem solely from the lack of a specific nutrient. An actual vitamin D deficiency results in bone disease, such as rickets, which is rare in the United States.
On the other hand, lower-than-optimal levels of specific vitamins, including vitamin D, may increase your risk of numerous health problems, even though they are not solely responsible for these problems. “Insufficiency” may be a better term for these lower levels than “vitamin D deficiency”.
So far, the most clearly established benefit of vitamin D is that it helps the body absorb calcium and therefore promotes healthy bones. However, a steady drumbeat of studies beginning in the 1980s started to build a case that low blood levels of D were connected with a variety of chronic health problems, leading to claims by a number of researchers that the RDA for D was way too low. The confusion and controversy surrounding optimal vitamin D intake and blood values prompted the U.S. and Canadian governments to request that the Institute of Medicine review the evidence on vitamin D and calcium and update the DRIs.
To learn more about the vitamins and minerals you need to stay healthy, read Making Sense of Vitamins and Minerals, a Special Health Report from Harvard Medical School.
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What Does Vitamin D Do
Probably one of the most talked-about vitamin in Canada is vitamin D, and for good reason!
Vitamin D is known as a vitamin but it is actually a hormone that is manufactured in our skin when we come in direct contact with ultraviolet rays from sun exposure.
As you can imagine, here in Canada we dont always have so much of that which is why the risk for vitamin D deficiency is typically higher in the Northern Hemisphere.
According to Health Canada, a minimum of 40% of Canadians may not meet the vitamin D requirements during the wintertime .
So why is vitamin D important? The benefits of vitamin D in the body are vast as it plays an influential role in many health outcomes. Vitamin D plays a significant role in overall health but particularly in immune and bone health. It is needed for the absorption of calcium and bone mineralization as it enhances the absorption of this mineral in the intestines .
Too little levels of vitamin D can result in low calcium levels in the blood, which can decrease bone density and increase the risk of brittle bones and bone diseases. In combination with calcium, having adequate vitamin D levels is essential for strong and healthy bones.
You Value Is Higher Than 150 Ng/ml
These values could harm your health. You should therefore take steps to reduce your 25D value to below 100 ng/ml. To achieve this, simply stop taking vitamin D dietary supplements and avoid sunbathing. After roughly 3 months, have your 25D levels retested. After your Vitamin D value is back in the normal range, adjust your vitamin D intake accordingly.
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How Much Vitamin D Should I Take For Optimal Health
Your need for vitamin D goes up if any of these factors apply to you:
- You know youre already deficient in vitamin D
- You have dark skin
- Youre an older adult over 70 . Infants, children and older adults are all at risk for low vitamin D.
- You spend little time outdoors or always wear sunscreen when exposed to sunlight
- Youre a shift worker, health care worker or another indoor worker, which means you get little outdoor time and sunlight exposure
- Youre overweight or obese
- You are a nursing home resident or hospitalized patient
- You have a health condition, such as celiac disease, Crohns disease or cystic fibrosis, that interferes with absorption and processing of vitamin D in the intestines, kidneys or liver
- Breast-fed infants are also at risk for vitamin D deficiency, which is why supplementing is recommended
How much vitamin D should women take per day?
According to the USDA and National Institutes of Health, the standard recommendation of vitamin D that adult women should take in order to prevent deficiency is between 600 to 800 international units per day, depending on age. The exact number is debatable, and some experts feel that a higher dose of vitamin D, around 2,ooo to 5,000 IU per day, may be more beneficial.
How much vitamin D should men take per day?
The standard recommendation for adult men is also between 600 to 800 IU of vitamin D per day. Adults over 70 should supplement with more, at least 800 IU per day, while younger adults need at least 600 IU daily.
Men Or Women At Risk For Fracture Or Osteoporosis
1,200 mg calcium and 2040 mcg of vitamin D
There is evidence of risks of taking too much calcium through supplements. However, postmenopausal women at increased risk for fractures or osteoporosis need more calcium and vitamin D. If a woman with these characteristics is meeting her RDA through food, it is best that she not add a calcium supplement. If she does not eat dairy, she may need a supplement. If she has a balanced diet, she may only need an additional 500 mg of calcium.
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Which Type Of Vitamin D Should I Take
Most supplements contain vitamin D3, also known as cholecalciferol. Studies suggest that this increases blood levels a little better than vitamin D2 .
Both these versions of vitamin D require processing by the liver and kidneys. People with liver or kidney disease may need to get a special type of supplement from their doctors.
Although Vitamin D supplements are usually taken daily, they also come in higher doses, which may be prescribed for weekly or even monthly dosing.
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Special Precautions And Warnings
When taken by mouthPregnancy and breast-feedingChildrenHardening of the arteries A type of fungal infection called histoplasmosisHigh levels of calcium in the bloodOver-active parathyroid gland LymphomaKidney diseaseA disease that causes swelling in body organs, usually the lungs or lymph nodes Tuberculosis
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Signs Of Deficiency And Toxicity
Deficiency
Vitamin D deficiency may occur from a lack in the diet, poor absorption, or having a metabolic need for higher amounts. If one is not eating enough vitamin D and does not receive enough ultraviolet sun exposure over an extended period , a deficiency may arise. People who cannot tolerate or do not eat milk, eggs, and fish, such as those with a lactose intolerance or who follow a vegan diet, are at higher risk for a deficiency. Other people at high risk of vitamin D deficiency include:
- People with inflammatory bowel disease or other conditions that disrupt the normal digestion of fat. Vitamin D is a fat-soluble vitamin that depends on the guts ability to absorb dietary fat.
- People who are obese tend to have lower blood vitamin D levels. Vitamin D accumulates in excess fat tissues but is not easily available for use by the body when needed. Higher doses of vitamin D supplementation may be needed to achieve a desirable blood level. Conversely, blood levels of vitamin D rise when obese people lose weight.
- People who have undergone gastric bypass surgery, which typically removes the upper part of the small intestine where vitamin D is absorbed.
Conditions resulting from prolonged vitamin D deficiency:
Toxicity
Symptoms of toxicity:
- Irregular heart beat
- Hardening of blood vessels and tissues due to increased blood levels of calcium, potentially leading to damage of the heart and kidneys
Can Vitamin D3 Cause Hair Loss
There is some evidence that vitamin D deficiency may be a contributing factor to hair loss. One study found that women with hair loss had significantly lower levels of vitamin D than women without hair loss.
While more research is needed to determine whether vitamin D supplementation can help with hair loss, it may be worth taking a supplement if you’re deficient in this nutrient. Aim for 600 IU of vitamin D per day. You can also get your vitamin D levels checked by a doctor to see if you need to supplement.
If you’re concerned about hair loss, be sure to talk to your doctor. While vitamin D deficiency may be a factor in hair loss, there are many other potential causes. Only a medical professional can diagnose the cause of your hair loss and recommend treatment options.
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Why Wearing Sunscreen Can Affect Vitamin D Absorption
While wearing sunscreen daily is key to help prevent sunburns, premature aging, and skin cancer, this healthy habit can also affect how much vitamin D your skin synthesizes from the sun.
To get your fix, aim to spend 10 to 15 minutes outdoors without sunscreen, Foroutan says. It can help get your levels where they need to be, she says, echoing information from Harvard Health Publishing.
Calcium And Vitamin D Requirements
As new scientific research emerges, recommendations change. We are now rethinking how much calcium and vitamin D is needed for good bone health. There is increasing evidence that too much calcium from supplements is not likely to be a benefit and worse, can be harmful. This was underscored in the 2010 and 2018 reports from the US Preventive Services Task Force recommending that premenopausal women and men may not benefit from calcium supplements.
The recommended dietary allowances are goals established by the Institutes of Medicine the RDA varies with age, gender, and other factors. These amounts would be sufficient for 97% of the US population.
Mounting evidence shows that too little calcium in the diet is harmful, but too much calcium also may be harmful.
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Vitamin D For Depression
Its estimated that about 6.7% of adults in the United States have depression. But, fewer than 25% of people with depression receive treatment.
Vitamin D supplementation may be a healthy and cheap way to deal with depression, though! Most noteworthy, vitamin D supplementation has no side effects. Even high daily dosages of 10,000 IU are pretty safe.
Moreover, even just one dose of 100,000 IU can decrease symptoms of depression.
Certainly, vitamin D is vital for the proper development of the brain. Hence, pregnant women should check their vitamin D levels!
For instance, there are vitamin D receptors in the hypothalamus, which may be important in neuroendocrine functioning. Also, vitamin D is important for cellular proliferation and nerve signaling.
Vitamin D: The Healthy Aging Dose
Confused by all the back and forth in the media about vitamin D?
Dont be. Theres actually a pretty easy and straightforward approach that most older adults can take.
In this post, Ill explain what I recommend to most of my older patients, and why.
Ill also address the following frequently asked questions:
- Which type of Vitamin D should I take?
- Do I need to have my vitamin D blood level checked?
- What should ones vitamin D level be?
- Will vitamin D really prevent falls or fractures?
- Will vitamin D prevent dementia, cancer, and/or premature death?
- I am outside a lot. Do I need a vitamin D supplement?
- I heard that a higher level of vitamin D is better for you. How much is too much?
By the way, I maintain this post in part because a few years back, I was disappointed by the recent NY Times article Why Are So Many People Popping Vitamin D?
Among other things, that article should have had a different headline. The key problem the article described is that there are too many people being tested for vitamin D. The article did not make the case that too many people are taking vitamin D supplements.
In fact, vitamin D supplementation remains recommended by experts. And as Ill explain below, there are good reasons to believe that vitamin D supplementation is especially useful for older adults.
Now, I do agree with the article in that many people seem to have unrealistic expectations of what vitamin D can do for them.
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There Are Ways To Get More Vitamin D In The Winter Or On Cloudy Days
Sources of vitamin D in the diet are actually quite limited … the biggest source of vitamin D in fatty fish so, typically salmon, cod liver oil, a little bit in canned sardines or canned mackerel, Sfeir said.
According to the U.S. Department of Agriculture, cod liver oil has 450 IU of vitamin D, and 3 ounces of sockeye salmon has 447 IU a large portion of an adults suggested 600 IU daily intake.
Certain foods are fortified with vitamin D, like milk and orange juice, Sfeir noted. But vitamin D supplements available from your drugstore are the biggest source of consumable vitamin D, Sfeir said.
