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Posts Tagged ‘Essential nutrient’

Medical Headline Misinformation Strikes Again: Claims About Vitamin D

Reporter: Stephen J. Williams, Ph.D.

A recent posting by a group called the Vitamin D Council (and put on this site) had referred to, and misquoted, the Mayo Clinic site on the role of vitamin D on various diseases. At first I was curious if this was actually reported on the Mayo site on claims of prevention of various cancers (as results from retrospective studies had been conflicting) and originally had made some strong comments. From comments made from this post I do agree that there is strong evidence about vitamin D supplementation for the prevention of rickets but as Mayo reviewed claims about vitamin D supplementation and prevention of certain diseases such as cancers and heart disease may not be as strong as some suggest.  My main concern was : is the clinical evidence strong enough for the role of vitamin D supplementation in a wide array of diseases and did Mayo make the claims as suggested in some media reports?  Actually Mayo does a very thorough job of determining the clinical evidence and the focus of vitamins and cancer risk will be a point of further discussion.

After consulting the Mayo clinic website it appears that the Vitamin D Council site had indeed misquoted and misrepresented the medical information contained within the Mayo Clinic website.

Medical Misinformation Is Probably The Most Hazardous and Biggest Risk Impacting a Healthy Lifestyle

The site had made numerous claims on role of vitamin D3 (cholecalciferol) in numerous diseases; making it appear there were definitive links between low vitamin D3 and risk of hypertension, cancer, depression and diabetes.

A little background on Vitamin D

From Wikipedia

Vitamin D refers to a group of fat-soluble secosteroids responsible for enhancing intestinal absorption of calcium, iron, magnesium, phosphate and zinc. In humans, the most important compounds in this group are vitamin D3 (also known as cholecalciferol) and vitamin D2 (ergocalciferol).[1] Cholecalciferol and ergocalciferol can be ingested from the diet and from supplements.[1][2][3] Very few foods contain vitamin D; synthesis of vitamin D (specifically cholecalciferol) in the skin is the major natural sources of the vitamin. Dermal synthesis of vitamin D from cholesterol is dependent on sun exposure (specifically UVB radiation).Vitamin D has a significant role in calcium homeostasis and metabolism. Its discovery was due to effort to find the dietary substance lacking in rickets (the childhood form of osteomalacia).[4]

also from Widipedia on Vitamin D toxicity

Vitamin D toxicity

Vitamin D toxicity is rare.[20] It is caused by supplementing with high doses of vitamin D rather than sunlight. The threshold for vitamin D toxicity has not been established; however, the tolerable upper intake level (UL), according to some research, is 4,000 IU/day for ages 9–71.[7] Whereas another research concludes that in healthy adults, sustained intake of more than 1250 μg/day (50,000 IU) can produce overt toxicity after several months and can increase serum 25-hydroxyvitamin D levels to 150 ng/ml and greater;[20][56] those with certain medical conditions, such as primary hyperparathyroidism,[57] are far more sensitive to vitamin D and develop hypercalcemia in response to any increase in vitamin D nutrition, while maternal hypercalcemia during pregnancy may increase fetal sensitivity to effects of vitamin D and lead to a syndrome of mental retardation and facial deformities.[57][58]

After being commissioned by the Canadian and American governments, the Institute of Medicine (IOM) as of 30 November 2010, has increased the tolerable upper limit (UL) to 2,500 IU per day for ages 1–3 years, 3,000 IU per day for ages 4–8 years and 4,000 IU per day for ages 9–71+ years (including pregnant or lactating women).[7]

Published cases of toxicity involving hypercalcemia in which the vitamin D dose and the 25-hydroxy-vitamin D levels are known all involve an intake of ≥40,000 IU (1,000 μg) per day.[57] Recommending supplementation, when those supposedly in need of it are labeled healthy, has proved contentious, and doubt exists concerning long-term effects of attaining and maintaining high serum 25(OH)D by supplementation.[61]

From the Mayo Clinic Website on Vitamin D

The Mayo Clinic has done a wonderful job curating the uses and proposed uses of vitamin D for various diseases and rates the evidence using a grading system A-F (as shown below):

Key to grades

A STRONG scientific evidence FOR THIS USE

B GOOD scientific evidence FOR THIS USE

C UNCLEAR scientific evidence for this use

D Fair scientific evidence AGAINST THIS USE (it may not work)

F Strong scientific evidence AGAINST THIS USE (it likely does not work)

Mayo has information for other natural products as well. As described below (and on the Mayo site here) most of the supposed evidence fails their criteria for a strong clinical link between diseases such as heart disease, hypertension, cancer and vitamin D (either parental or D3) levels.

The important take-home from the Mayo site is that there is strong evidence for the use of vitamin D in diseases related to the known mechanism of vitamin D such as low serum phosphate either due to kidney disease (Fanconi syndrome) or familial hypophosphatemia or in diseases surrounding bone metabolism like osteomalacia, rickets, dental cavities and even as a treatment for psoriasis or underactive parathyroid.

However most indications like hypertension, stroke, cancer prevention or treatment (other than supportive therapy for low vitamin D levels) get a poor grade (C or D) for clinical correlation from Mayo Clinic.

A Post in the Near Future will be a Curation of Validated Clinical Studies on Effects of Vitamins on Cancer Risk.

Below is taken from the Mayo Site:

Evidence

These uses have been tested in humans or animals.  Safety and effectiveness have not always been proven.  Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

Grading rationale

Evidence grade Condition to which grade level applies
A

Deficiency (phosphate)

Familial hypophosphatemia is a rare, inherited condition in which there are low blood levels of phosphate and problems with vitamin D metabolism. It is a form of rickets. Taking calcitriol or dihydrotachysterol by mouth along with phosphate supplements is effective for treating bone disorders in people with this disease. Those with this disorder should be monitored by a medical professional.

A

Kidney disease (causing low phosphate levels)

Fanconi syndrome is a kidney disease in which nutrients, including phosphate, are lost in the urine instead of being reabsorbed by the body. Taking ergocalciferol by mouth is effective for treating low phosphate levels caused by Fanconi syndrome.

A

Osteomalacia (bone softening in adults)

Adults who have severe vitamin D deficiency may experience bone pain and softness, as well as muscle weakness. Osteomalacia may be found among the following people: those who are elderly and have diets low in vitamin D; those with problems absorbing vitamin D; those without enough sun exposure; those who undergo stomach or intestine surgery; those with bone disease caused by aluminum; those with chronic liver disease; or those with bone disease associated with kidney problems. Treatment for osteomalacia depends on the cause of the disease and often includes pain control and surgery, as well as vitamin D and phosphate-binding agents.

A

Psoriasis (disorder causing skin redness and irritation)

Many different approaches are used to treat psoriasis, including light therapy, stress reduction, moisturizers, or salicylic acid. For more severe cases, calcipotriene (Dovonex®), a man-made substance similar to vitamin D3, may help control skin cell growth. This agent is a first-line treatment for mild-to-moderate psoriasis. Calcipotriene is also available with betamethasone and may be safe for up to one year. Vitamin D3 (tacalcitol) ointment or high doses of becocalcidiol applied to the skin are also thought to be safe and well-tolerated.

A

Rickets (bone weakening in children)

Rickets may develop in children who have vitamin D deficiency caused by a diet low in vitamin D, a lack of sunlight, or both. Babies fed only breast milk (without supplemental vitamin D) may also develop rickets. Ergocalciferol or cholecalciferol is effective for treating rickets caused by vitamin D deficiency. Calcitriol should be used in those with kidney failure. Treatment should be under medical supervision.

A

Thyroid conditions (causing low calcium levels)

Low levels of parathyroid hormone may occur after surgery to remove the parathyroid glands. Taking high doses of dihydrotachysterol, calcitriol, or ergocalciferol by mouth, with or without calcium, may help increase calcium levels in people with this type of thyroid problem. Increasing calcium intake, with or without vitamin D, may reduce the risk of underactive parathyroid glands.

A

Thyroid conditions (due to low vitamin D levels)

Some people may have overactive parathyroid glands due to low levels of vitamin D, and vitamin D is the first treatment for this disorder. For people who have overactive parathyroid glands due to other causes, surgery to remove the glands is often recommended. Studies suggest that vitamin D may help reduce the risk of further thyroid problems after undergoing partial or total removal of the parathyroid glands.

A

Vitamin D deficiency

Vitamin D deficiency is associated with many conditions, including bone loss, kidney disease, lung disorders, diabetes, stomach and intestine problems, and heart disease. Vitamin D supplementation has been found to help prevent or treat vitamin D deficiency.

B

Dental cavities

Much evidence has shown that vitamin D helps prevent cavities; however, more high-quality research is needed to further support this finding.

B

Renal osteodystrophy (bone problems due to chronic kidney failure)

Renal osteodystrophy refers to the bone problems that occur in people with chronic kidney failure. Calcifediol or ergocalciferol taken by mouth may help prevent this condition in people with chronic kidney failure who are undergoing treatment.

C

Autoimmune diseases

Vitamin D may reduce inflammation and help prevent autoimmune diseases, including rheumatoid arthritis, multiple sclerosis, and Crohn’s disease. However, further high-quality research is needed to confirm these results.

C

Bone density (children)

Vitamin D improves bone density in children who are vitamin D deficient. However, results are unclear and more research is needed.

C

Bone diseases (kidney disease or kidney transplant)

Vitamin D has been studied for people with chronic kidney disease. The use of substances similar to vitamin D has been found to increase bone density in people with kidney disease. The effect of vitamin D itself is unclear. Further research is needed before conclusions can be made.

C

Cancer prevention (breast, colorectal, prostate, other)

Many studies have looked at the effects of vitamin D on cancer. Positive results have been reported with the use of vitamin D alone or with calcium. Vitamin D intake with or without calcium has been studied for colorectal, cervical, breast, and prostate cancer. A reduced risk of colorectal cancer has been shown with vitamin D supplementation. However, there is a lack of consistent or strong evidence. Further study is needed.

C

Fibromyalgia (long-term, body-wide pain)

Vitamin D has been studied for the treatment of fibromyalgia, but evidence is lacking in support of its effectiveness. Further study is needed.

C

Fractures (prevention)

Conflicting results have been found on the use of vitamin D for fracture prevention. The combination of alfacalcidol and alendronate has been found to reduce the risk of falls and fractures. However, further high-quality research is needed before firm conclusions can be made.

C

Hepatic osteodystrophy (bone disease in people with liver disease)

Metabolic bone disease is common among people with chronic liver disease, and osteoporosis accounts for the majority of cases. Varying degrees of poor calcium absorption may occur in people with chronic liver disease due to malnutrition and vitamin D deficiency. Vitamin D taken by mouth or injected may play a role in the management of this condition.

C

High blood pressure

Low levels of vitamin D may be linked to high blood pressure. Blood pressure is often higher during the winter season, at a further distance from the equator, and in people with dark skin pigmentation. However, the evidence is unclear. More research is needed in this area. People who have high blood pressure should be managed by a medical professional.

C

Immune function

Early research suggests that vitamin D and similar compounds, such as alfacalcidol, may impact immune function. Vitamin D added to standard therapy may benefit people with infectious disease. More studies are needed to confirm these results.

C

Seasonal affective disorder (SAD)

SAD is a form of depression that occurs during the winter months, possibly due to reduced exposure to sunlight. In one study, vitamin D was found to be better than light therapy in the treatment of SAD. Further studies are necessary to confirm these findings.

C

Stroke

Higher levels of vitamin D may decrease the risk of stroke. However, further study is needed to confirm the use of vitamin D for this condition.

C

Type 1 diabetes

Some studies suggest that vitamin D may help prevent the development of type 1 diabetes. However, there is a lack of strong evidence to support this finding.

C

Type 2 diabetes

Vitamin D has mixed effects on blood sugar and insulin sensitivity. It is often studied in combination with calcium. Further research is needed to confirm these results.

D

Cancer treatment (prostate)

Evidence suggests a lack of effect of vitamin D as a part of cancer treatment for prostate cancer. Further study is needed using other formulations of vitamin D and other types of cancer.

D

Heart disease

Vitamin D is recognized as being important for heart health. Overall, research is not consistent, and some studies have found negative effects of vitamin D on heart health. More high-quality research is needed to make a firm conclusion.

D

High cholesterol

Many studies have looked at the effects of vitamin D alone or in combination with other agents for high cholesterol, but results are inconsistent. Some negative effects have been reported. More research is needed on the use of vitamin D alone or in combination with calcium.

Other related articles on Vitamins and Disease were published in this Open Access Online Scientific Journal, include the following:

Multivitamins – Don’t help Extend Life or ward off Heart Disease and Improve state of Memory Loss

Diet and Diabetes

What do you know about Plants and Neutraceuticals?

Malnutrition in India, high newborn death rate and stunting of children age under five years

Omega-3 fatty acids, depleting the source, and protein insufficiency in renal disease

American Diet is LOW in four important Nutrients that have a direct bearing on Aging and the Brain

Parathyroids and Bone Metabolism

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Benefits of Functional Foods in Nutrient Imbalance of Vulnerable Populations

Reporter and Curator: Dr. Sudipta Saha, Ph.D.

There are clear distinctions between a food and a drug. Nutraceuticals, however, occupy a place between the two. Nutraceuticals are naturally derived phytochemicals with potential health benefits and without the characteristics of being essential nutrients. Foods that contain these non-essential substances with potential health benefits may qualify as “functional foods.” As defined by the Food and Nutrition Board of the National Academy of Sciences, the term functional food refers to foods that provide health benefits beyond basic nutrition. Examples of these are

  • psyllium seeds (soluble fiber),
  • soy foods (isoflavones),
  • cranberry juice (proanthocyanidins),
  • purple grape juice (resveratrol),
  • tomatoes (lycopene), and
  • green tea (catechins).

The bioactive components of functional foods:

  • flavonols,
  • monomeric and polymeric flavan-3-ols,
  • highly coloured anthocyanins, and
  • phenolic acids

may be increased in or added to traditional foods. An example is a genetically modified tomato high in lycopene, which has potent antioxidant capabilities.

The risk of nutrient imbalance is highest in vulnerable populations unable to access essential or conditionally essential nutrients. To a large extent, the

  • very young and the
  • frail elderly

are the select groups who might benefit most from alleviating this risk. The lack of adequate nutrition may be due to seasonal and unexpected losses of agricultural produce; however, poverty is a factor on a global scale as a result of growing economic disparities. The question then becomes what role functional foods offer to improve recognized population nutritional deficiencies. The range of work being done on functional foods is impressive, from

  • modified oils that contain heart-healthy ω-3 fatty acids to
  • cassava plants developed with an increased protein content to help counter malnutrition in developing nations.

However, the nutraceutical industry has responded to and relies on the untested expectations of the healthiest members of the world’s population rather than its more vulnerable ones. Due largely to economic causes, those in need are less likely to receive the benefits of nutraceuticals from whole foods or from manufactured foods or supplements. This is particularly striking where the source is locally available and extracted for commerce but is unaffordable or unavailable to the native population.

The rapid advances in biotechnology and functional foods confront us with a need to address the benefits of these with regard to improving health and managing or decreasing disease risks. Conventional dietary recommendations have focused on the consumption of fruits, vegetables, legumes, and whole grains, a decreased sugar intake, and an emphasis on plant oils, recommendations that have unproved benefits for the prevention of chronic diseases and that have complexities involving individual, environmental, and genetic influences.

Although the potential benefits of phytochemicals could have an impact on health status for vulnerable populations, the recommendations focused on plant foods do not address the primary concerns of the undernutrition associated with a poor quality of protein intake. Taken individually, plant sources do not provide a balanced amino acid profile necessary for protein synthesis, being deficient in lysine and/or methionine. Animal sources of protein, specifically meat and fish, also provide essential fatty acids not found in plant sources of protein and that may be otherwise limited. In addition, plants may contain antinutritional factors (wheat, cassava roots, cabbages, soy beans), and plant-based diets may be deficient in important essential nutrients.

Programs must focus on the sustainable production and local processing of indigenous products that can be used by needy populations to improve their nutritional intake and enhance economic stability. In addition, dietary recommendations must not exclude important sources of nutrition for more vulnerable populations by focusing primarily on plant-based sources of food, decreasing saturated fat, and de-emphasizing the importance of high-value biologic protein. The global economic crisis has touched the lives of 80% of the population in most developing countries with a threat to the development of a generation of children (approximately 250 million) who are most vulnerable in the first 2 years of life. An investment in nutrition in this circumstance has a high value, and the use of complementary food supplements to increase a meal’s nutrient content is warranted.

A recent proposal has concluded there are health benefits for foods and food constituents put together in a synergic diet pattern, suggesting that the interrelation between constituents within whole foods is significant, and has recommended dietary variety and the selection of nutrient-rich foods. Providing vulnerable populations with an adequate supply of whole foods should take precedence over the recommendation of food products in supplying not only essential macro- and micronutrients and energy but also phytochemicals whose value to the human diet is still to be determined.

Source References:

http://www.sciencedirect.com/science/article/pii/S0899900711003133

 

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