Category: Nutrition

What is the right dose of vitamin D and could higher amounts do harm to our bodies?

What dose of vitamin D is the right amount; 400 international units (IU) per day or 4,000 IU per day or 10, 000 IU per day?

A clinical trial in Canada has found that taking vitamin D at high dosages is worthless and could even reduce bone density.

Some signs of taking too much vitamin D include:

• dehydration,
• fatigue,
• nausea,
• muscle weakness,
• thirst,
• and constipation.

Our skin makes vitamin D from exposure to sunlight and during the summer it only takes 15 minutes to get enough vitamin D for the day.

During winter time people in many countries such as Canada can’t get enough sunlight so the advice is to take a vitamin D supplement.

Our body needs vitamin D to absorb calcium for healthy bones, immune function, and mental health.

The Canadian study focuses on the necessity for vitamin D supplementation regarding bone density and bone strength.

They conducted a 3-year study on 311 healthy adult aged 55 to 70.

One group received 400 IU of vitamin D3 daily, the other 4,000 IU per day, and the third 10,000 IU per day.

Calcium and vitamin D together are important for bone health, therefore, the research team also provided participants a calcium  supplement of 1,200 mg daily.

Health Canada recommends a dosage of 600 IU to 800 IU of vitamin D per day for a healthy adult aged 70+.

Osteoporosis Canada’s recommendation for vitamin D daily intake is 400 to 2,000 IU to avoid the bone loss disease.

Moreover, some individuals taking even a higher amount due to a vitamin D deficiency or a medical condition.

Therefore, it brings us back to this question of what is the right amount and what dosage of vitamin D can be harmful.

The study examined participants’ bone mineral density (BMD) by measuring levels of calcium and other minerals in the bone.

The risk of breaking a bone increases when the bone density is lower.

The BMD examinations showed that bone loss was significantly different between the three dosage of vitamin D groups.

Over the 3-year study, people on 10,000 IU of vitamin D saw a 3.6 percent reduction in their BMD while for the 4,000 IU group the reduction was 2.6 percent, and for the 400 IU group a 1.4 percent drop.

In short, the findings contradicted the hype about higher doses of vitamin D helping to increase bone density and build strong bones.

In this study, those who were on 10,000 IU vitamin D per day had the biggest decrease in bone density, suggesting a higher dosage can cause damage to the bones.

Professor Steven Boyd, the study’s co-author, said:

“with XtremeCT, the latest in bone imaging technology, we were able to find dose-dependent changes over the three years.

However, we were surprised to find that instead of bone gain with higher doses, the group with the highest dose lost bone the fastest.

That amount of bone loss with 10,000 IU daily is not enough to risk a fracture over a three-year period, but our findings suggest that for healthy adults, vitamin D doses at levels recommended by Osteoporosis Canada (400-2000 IU daily) are adequate for bone health.”

In addition, the study found that vitamin D supplements at higher doses, when taken for a long period, could increase risk of developing hypercalciuria, high amounts of calcium in the urine which can cause kidney stones.

The study was published in the Journal of the American Medical Association (Burt et al., 2019).

Up to one-in-eight people may have this vitamin deficiency.

Thinking and memory problems can be signs of vitamin B12 deficiency, research finds.

Deficiency in the vitamin has been linked to brain shrinkage with age and even dementia.

Vitamin B12 is crucial to the production of red blood cells and the healthy functioning of brain cells.

Its effect on cognitive decline is likely down to its involvement in in the production of myelin.

Myelin is a material that surrounds neurons (brain cells) and also the connections between them, known as axons.

Fortunately, vitamin B12 deficiency is easy to correct either with supplementation or a change in diet.

Foods high in vitamin B12 include dairy, beef, salmon, eggs and low-fat milk.

Fortified breakfast cereals also contain vitamin B12.

Reviewing the methods of detecting levels of B12 in the body, Dr Georgios Tsiminis and colleagues write:

“Increased levels of vitamin B12 have been shown to reduce the likelihood of older adults transitioning from mild cognitive impairment to dementia and in at least one case may help reverse the symptoms of frontotemporal dementia, as previously shown in a B12 recovery treatment program.

The growing number of studies indicating the significance of the relationship between vitamin B12 and cognitive health cannot be ignored.”

People who may have difficulty getting enough vitamin B12 include vegetarians, older people and those with some digestive disorders, such as Crohn’s disease.

Dr Georgios Tsiminis, the study’s first author, said:

“Vitamin B12 deficiency has been shown to be a potential modifiable risk factor for dementia and Alzheimer’s disease and is associated with cognitive decline.

Older adults are particularly at risk of B12 deficiency due to age-related reduction in absorbing vitamin B12 received through their diet.

The study was published in the journal Applied Spectroscopy Reviews (Tsiminis et al., 2019).

A walk of as little 20 minutes in the daylight is enough to provide sufficient levels of vitamin D.

Sleepiness and fatigue during the day can be a sign of vitamin D deficiency, studies find.

People with lower vitamin D levels can experience less sleep overall and more waking during the night.

People experience worse sleep, the lower their vitamin D levels are.

Vitamin D may affect critical neurotransmitters and inflammatory markers.

Fatigue may also be due to problems in the body’s mitochondria.

Mitochondria are the ‘power stations’ within each cell in our body.

Without vitamin D, the mitochondria cannot work efficiently.

Around half the world’s population is deficient in vitamin D.

Foods that are rich in vitamin D include oily fish and eggs, but most people get their vitamin D from the action of sunlight on the skin.

Other signs of vitamin D deficiency include low mood, muscle fatigue, difficulties with learning and memory, gut problems and headaches.

One study of global populations has found that vitamin D deficiency is a widespread problem in many areas.

Vitamin D is vital for bone mineralisation, so deficiency can lead to a greater risk of fracture.

Some of the main risk factors for having low vitamin D levels are:

• being female,
• poor dietary habits,
• being older,
• living in northerly areas,
• and less exposure to sunlight.

Urbanisation means many people live and work indoors.

A walk of as little 20 minutes in the daylight is enough to provide sufficient levels of vitamin D.

The conclusions come from a review of the research carried out across six continents.

The results showed the risk of vitamin D deficiency is highest in the Middle East and South Asia, largely because of traditional clothing that blocks the action of sunlight on the skin.

The study was published in the journal Osteoporosis International (Mithal et al., 2009).

People with vitamin B12 deficiency were three times more likely to be suffering this problem.

Feeling depressed can be a sign of vitamin B12 deficiency, a study finds.

People with a vitamin B12 deficiency are three times more likely to be experiencing ‘melancholic’ depression.

Melancholic depression mostly involves depressed mood.

Some of the other most common symptoms of depression are decreased interest in life or pleasure, energy loss and concentration problems.

The study also found a link between low folate intake and depression.

Folates include vitamin B9, folacin and folic acid.

People with a low intake of folates were 50 percent more likely to be experiencing melancholic depression.

The research included 2,806 Finnish people whose nutritional status and depression symptoms were assessed.

Although vitamin B12 and folates were linked to melancholic depression, the same link was not seen with non-melancholic depression.

Symptoms of non-melancholic depression cluster around anxiety and low self-esteem, with less emphasis on depressed mood.

Dr Jussi Seppälä, the study’s first author, said:

“The findings have practical implications in the care of patients with depressive symptoms.

For example, it may be wise to avoid medication causing weight gain among patients with non-melancholic depression, whereas melancholic depressive symptoms may call for a closer look at the quality of the patient’s diet.”

Boosting B12 and folate intake

Vitamin B12 deficiency is easy to rectify with supplements or by dietary changes.

The body uses vitamin B12 to make red blood cells and to keep the nervous system healthy.

Other common signs of vitamin B12 deficiency include experiencing muscle weakness and being constipated.

Meanwhile, some of the best dietary sources of folates include:

• vegetables,
• fruits,
• liver,
• and whole-grains.

Folate levels are particularly high in chickpeas, yeast extract, lentils and broad beans.

The study was published in the Journal of Affective Disorders (Seppälä et al., 2012).

The brain loses about half a teaspoon of cells each year.

People eating a diet rich in vegetables, fruit, nuts, whole grains, dairy and fish have bigger brains, research concludes.

The best diet for the brain also had a limited intake of sugary drinks.

Diet could be one useful way of combating the natural shrinkage of the brain with age.

The brain loses around 3.6 millilitres of volume for each year of aging — that’s about half a teaspoon of brain cells.

Dr Meike W. Vernooij, who led the study, said:

“People with greater brain volume have been shown in other studies to have better cognitive abilities, so initiatives that help improve diet quality may be a good strategy to maintain thinking skills in older adults.

More research is needed to confirm these results and to examine the pathways through which diet can affect the brain.”

The Dutch study of 4,213 people asked people about their intake of vegetables, fruit, whole grain products, legumes, nuts, dairy, fish, tea, unsaturated fats and oils of total fats, red and processed meat, sugary beverages, alcohol and salt.

Scans determined their brain volume, white matter lesions and any brain bleeds.

The best diet was similar to the so-called ‘Mediterranean diet‘, which is also rich in fish, vegetables and nuts.

Those with a better diet had, on average, 2 millilitres more brain volume.

There wasn’t one food that was best for the brain, it was about the combination, Dr Vernooij said:

“There are many complex interactions that can occur across different food components and nutrients and according to our research, people who ate a combination of healthier foods had larger brain tissue volumes.”

The study was published in the journal Neurology (Croll et al., 2018).

Up to 50 percent of the population of the world is deficient in vitamin D.

Daytime sleepiness can be a sign of vitamin D deficiency, research suggests.

People with low levels of vitamin D are likely to wake more during the night and to have less sleep overall.

Vitamin D levels are linked to both sleep quantity and quality.

From October to March many people in northern climes do not get enough vitamin D.

As many as 50 percent of the world’s population is thought to be deficient in vitamin D.

Most people need around 10 micrograms per day, which can also be obtained from supplements.

Other signs of vitamin D deficiency include low mood, muscle fatigue, difficulties with learning and memory, gut problems and headaches.

The vitamin is thought to play a role in regulating serotonin, a neurotransmitter important for mood.

Foods that are rich in vitamin D include oily fish and eggs, but most people get their vitamin D from the action of sunlight on the skin.

Vitamin D is critical to the functioning of the whole body.

Some of the main risk factors for having low vitamin D levels are:

• being female,
• poor dietary habits,
• being older,
• living in northerly areas,
• and less exposure to sunlight.

The study included 81 people who had sleep problems.

Vitamin D levels were found to be lowest in those with the most daytime sleepiness, the results revealed.

Dr David McCarty, the study’s first author, said:

“While we found a significant correlation between vitamin D and sleepiness, the relationship appears to be more complex than we had originally thought.

It’s important to now do a follow-up study and look deeper into this correlation.”

The study was published in the Journal of Clinical Sleep Medicine (McCarthy et al., 2012).