Dietary calcium doesn’t make your bones stronger after all

Although it is current practice to prescribe vitamin D and calcium together, particularly in post menopausal women, a six year study shows that the added calcium has no value.

The women were all over the age of 65 and had osteopenia. This is the stage before osteoporosis. 1,994 women were randomised to take zolendronic acid or placebo.  Bone mineral density was measured at the spin, total hip, femoral neck and total body three times at intervals.

The baseline BMD was unrelated to dietary calcium after controlling for age, height, weight, physical activity, alcohol intake, smoking and past HRT use when a cross section of women were studied.

Loss of BMD over the next six years was not related to the amount of dietary calcium ingested.

Bristow SM et al. Dietary Calcium intake and bone loss over six years in osteopenic post menopausal women. J Clin Endocrinol Metab. 2019 Mar 21.

My comment: Maybe time to ditch the calcium?

And while we are on the subject of bones, I’m pleased to say that another study has shown that high dose vitamin D supplementation does NOT increase kidney stone risk.

Over just over 3 years of taking 100,000 iu of vitamin D3 each month did not increase excess calcium in the blood or the onset of kidney stones in adults aged between 50 and 84 years.

This dose is equivalent to 3300 iu vit D3 a day, similar to what many of us in the know take.

158 people took part in the randomised trial. The number of people developing kidney stones was similar in each group and no one in the intervention group developed hypercalcaemia.  The groups self reported stones. No ultrasound was done which the authors say could have been more accurate.

Malihi Z et al. Monthly high dose vitamin D supplementation does not increase kidney stone risk or serum calcium: results from a randomised controlled trial. Am J Clin. Nutr. 2019 Apr 21

 

Chief Medical Officer Scotland: Vitamin D supplementation

From letter from Dr Catherine Calderwood Chief Medical Officer Scotland 
24 November 2017

New Recommendations on Vitamin D Supplementation

Vitamin D plays an important role in maintaining bone health throughout life. Vitamin D deficiency impairs the absorption of dietary calcium and phosphorous. This can lead to:
 Infants having muscle weakness and bone softening leading to rickets;
 Adults having muscle weakness and osteomalacia, which leads to bone pain and tenderness.
The most recent National Diet and Nutrition Survey shows that a proportion of the UK population has low vitamin D levels, which may put them at risk of the clinical consequences of vitamin D deficiency.
Last year, the Scientific Advisory Committee on Nutrition (SACN) made new recommendations on vitamin D and health.  The full report is available at:
https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/537616/SACNVitamin_D_and_Health_report.pdf

SACN considered all relevant evidence suggesting links between vitamin D and various health conditions and concluded that the risk of poor musculoskeletal health (e.g. rickets, osteomalacia) is increased with low vitamin D levels. SACN found insufficient evidence to draw firm conclusions on the impact of low vitamin D levels for non-musculoskeletal health outcomes.
The Scottish Government has now updated its advice on vitamin D in line with the new SACN recommendations as follows:

Everyone age 5 years and above should consider taking a daily supplement of 10μg of vitamin D, particularly during the winter months (October – March). Between late March/early April and September, the majority of people aged 5 years and above will probably obtain sufficient vitamin D from sunlight when they are outdoors, alongside foods that naturally contain or are fortified with vitamin D.
From October to March, everyone aged 5 and over will need to rely on dietary sources of vitamin D. Since vitamin D is found only in a small number of foods, it might be difficult to get enough from foods that naturally contain vitamin D and/or fortified foods alone.

Children aged 1 to 4 years of age should be given a daily supplement containing 10μg vitamin D. We recommend Healthy Start vitamin drops for all children in health.

A new-born baby’s vitamin D level depends on their mother’s levels near the birth and will be higher if the mother took a vitamin D supplement during pregnancy. Some mothers and babies have a higher risk of vitamin D deficiency, including those born to mothers who habitually wear clothes that cover most of their skin while outdooors and those from minority ethnic groups with dark skin such as those of African, African-Caribbean and South Asian origin.
However, as a precaution, we are now recommending that all babies from birth up to one year of age should be given a daily supplement of 8.5 to 10μg vitamin D. Babies who are formula fed do not require a vitamin D supplement if they are having at least 500ml per day, as infant formula already has added vitamin D.
We recommend Healthy Start vitamin drops for infants. Neonatologists and paediatricians may recommend alternatives for premature infants, children with clinical conditions or clinical presentations of vitamin D deficiency.
Advice for parents on vitamin D supplementation for breastfed babies must be carefully considered as there is a risk that infant formula could be viewed as superior to breastmilk. Breastfeeding is the normal way to feed infants. It has an important and lasting impact on the public health of the population and it is vital that we protect and support breastfeeding. It is recommended that you emphasise that the potential problem is related to a lack of sunlight in the UK, and that it affects the whole 
population, not just breastfed babies.
It is recommended that those at greatest risk of vitamin D deficiency take a daily supplement all year round. These groups include:
pregnant and breastfeeding mothers
 children under 5 years of age
 people who are not exposed to much sunlight, such as frail or housebound individuals, or those that cover their skin for cultural reasons; and
 people from minority ethnic groups with dark skin such as those of African, African-Caribbean and South Asian origin, because they require more sun exposure to make as much vitamin D.
General information leaflets on vitamin D for both the public and healthcare professionals have been updated to reflect these new recommendations and are available online at: http://www.gov.scot/Topics/Health/Healthy-Living/Food-Health/vitaminD
New guidance has been developed for parents and healthcare professionals to support parents to follow this new recommendation. This includes advice on how to administer vitamin D drops to young babies. It is available at:
http://www.gov.scot/Topics/Health/Healthy-Living/Food-Health/vitaminD
From April 2017, Healthy Start vitamins for women (which provide Vitamin D, folic acid and Vitamin C) are provided free of charge to all pregnant women in Scotland for the duration of their pregnancy, regardless of their entitlement to the Healthy Start scheme.
Breastfeeding women and children up to age 4 who are eligible for Healthy Start can also get free supplements containing vitamin D. Further information on the Healthy Start scheme can be found at http://www.healthystart.nhs.uk
Healthy Start vitamin drops for babies and children currently contain 7.5μg per 5 drops of vitamin D, as well as vitamin A and vitamin C. The new recommended dose for vitamin D is 8.5-10μg and vitamins containing the new recommended dose will be available from October 2018. In the meantime, parents should be advised to continue to give the current dosage of 5 drops per day.
In Scotland, NHS Boards are responsible for supplying Healthy Start vitamin supplements universally to pregnant women and to breastfeeding women and children who are eligible for the Healthy Start scheme. NHS Boards are also able to sell Healthy Start vitamins to families who are not eligible for Healthy Start. Some Health Boards have chosen to provide additional free vitamins for infants.
We are not currently in a position to extend universal provision of vitamin supplements to the whole of the Scottish population or to additional at risk groups including the elderly, women in the pre-conception period, infants or young children.
Vitamin D supplements for adults and children are also available to buy from most major supermarkets, high street pharmacies and health food stores.

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High dose Vitamin D improves cardiovascular health markers

Adapted from UK Medical News 17 July 2018

Several different health measures, all which improve your cardiovascular outcomes, have been found to result from high dose vitamin D supplementation. You are likely to need to take at least 4,000 iu a day though, depending on how much extra sunshine you are exposed to regularly.

A meta-analysis of 81 randomised controlled trials looked at almost one thousand patients randomised to taking supplements or to a control group who did not. The active and control groups were both roughly 5,000 each.  The durations of the trials varied but averaged out at ten months. The doses ranged from 400 iu a day to 12,000 iu a day. The average taken was 3,000 iu a day.

The outcomes were related to the blood level of vitamin D achieved. Levels had to be over 86 nmol/L to get benefits. You need to take over 4,000 iu a day to get vitamin D concentrations of 100 nmol/L or more.  My comment:This does mean that the minimum levels advised by the Scottish Chief Medical Officer last year are way too low to see the benefits discussed here.

So what extra benefits do you see?

lower systolic and diastolic blood pressure.

lower high sensitivity C reactive protein.

lower serum parathyroid hormone.

lower triglycerides.

lower total cholesterol.

lower low density lipoprotein.

high density lipoprotein increased.

All benefits were numerically small but did reach statistical significance. Cardiovascular outcomes were not measured directly, only blood markers and blood pressure.

Mirhosseini N et al. Vitamin D Supplementation. Serum 25(OH)D Concentrations and cardiovascular disease risk factors: A systematic review and meta-analysis. Front Cardiovasc Med. 2018 July 12.

 

 

 

 

Rowan Hillson:Diabetes and fracture risk

fractures.png

Adapted from:

 

Fractures and Diabetes

Rowan Hillson MBE

National Clinical Director for Diabetes England 2008-18

 

Practical Diabetes Jan/Feb 17

Summary

Fractures are more likely in diabetics compared to non- diabetics. Metabolic factors, an increased risk of falls, complications, infection, medications and the effects of low blood sugars all contribute. Neuropathy is a particular problem. This can cause an abnormal gait, stumbling, and a lack of awareness of actually sustaining injury. Even fractures may not cause anything like the expected pain. Charcot’s foot can cause lifelong disability. Visual problems also cause falls as does the effects of stroke and amputation.

It can help if someone goes round the house to check for trip hazards. Vitamin D supplements and increasing dietary calcium can help. Be aware that sulphonylureas can cause low blood sugars as well as insulin.

If a diabetic, particularly one who has neuropathy, presents with an injury they need careful evaluation to avoid missing fractures.

Fracture risk

Type one women  are six times more likely and type twos are twice as likely to sustain a fracture of the hip than a non diabetic. The longer the diabetes, the more the risk.

Low blood sugars

Low blood sugars are probably under reported by diabetics due to fears about losing their driving licences.

 

charcot-foot

Charcot Foot

Charcot foot presents as a swollen, red foot. There can be an underlying fracture. Because the person does not realise they have a fracture, they continue to weight bear, and this produces deformity of the foot. Best advice is that if a diabetic with neuropathy gets an unexplained inflammation of a foot that they stay off of it and get an urgent assessment by a multi disciplinary team at a diabetic foot clinic. Trouble is, that these are not available for all patients in the UK.

Drugs

Glitazones, eg Pioglitazone, doubles the risk of upper limb fracture in women.  Flozins such as Canaglifozin is suspected of increasing fracture rates and Sulphonyureas definitely do, but probably due to the hypoglycaemic effect.

Falls

Diabetics fall more than their non-diabetic counterparts. 18% of women over the age of 67 with diabetes fell at least once a year. The rate is higher in insulin users, neuropathy,  renal impairment, poor vision and low Hba1cs.

 

 

Low vitamin D doubles total mortality and dementia rates

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Being severely deficient in vitamin D is associated with a doubling of the risk of dementia according to a US study published in Neurology.

The Cardiovascular Health Study ran from the 1990s and tracked 1658 ambulatory citizens with no history of dementia or cardiovascular or cerebrovascular disease.

After a five year follow up time those who had vitamin D levels below 25 nmol/L had increased rates of dementia 2.2 times that of people who had levels over 50 nmol/L.

Researchers say that there are vitamin D receptors in the brain and vitamin D is thought to enhance macrophages that clear amyloid from the brain cells and reduce neuronal cell death.

(Based in article by Michael McCarthy in BMJ 16 August 14).

 

A combined European and US study showed that total mortality was increased by 57% for older adults with vitamin D levels below 25 nmol/L. Cardiovascular deaths and cancer deaths were increased in a dose responsive manner. 

(Based on and article by Stephen Robinson GP News 23 June 14)

Bizarrely the researchers didn’t think of the obvious solution, advise upping sun exposure or taking supplemental vitamin D, but decided that what this meant was that ill people were often stuck indoors and that was why they had low vitamin D levels.

The US study above does seem to contradict that view since all participants were ambulatory and had no known cardiovascular or cerebrovascular disease at the start of the study.  In my own practice in the west of Scotland most patients of all ages had very low levels of vitamin D. All walked into the surgery but had conditions that could have been affected by low vitamin D levels. The only patients who had levels over 50 nmol/L were taking supplements, cycled outdoors all year round, or used sunbeds.