In This Issue….

-           Does vitamin A affect our response to stress or pleasure?
-           How does vitamin D help us lose weight?
-           Is B12 deficiency common in thyroid conditions?
-           Why this mineral deficiency should be considered in some neurological cases
-           New research concludes vitamin E and selenium provide no benefit for cataract   prevention
-           Can vitamin D increase testosterone in women?

CLINICAL UPDATE – Does vitamin A affect our response to stress or pleasure?

Two recent animal studies investigated the effect of vitamin A on the brain’s response center, the hypothalamus, which controls the neurotransmitter response to outside stimuli – in this case, both positive (food rewards) or negative (stress). In the first study, higher vitamin A increased the expression of pleasure centers in the brain, specifically increasing activity in serotonin and dopamine receptors. The authors concluded that high vitamin A “modifies gene expression in food intake and reward pathways.”

In the second study, vitamin A deficiency caused a heightened response to restraint stress via higher production of the stress hormone, corticosterone. The heightened stress response in vitamin A deficient animals was mediated by the hypothalamic-pituitary-adrenal axis activation, supporting the conclusions of earlier evidence that vitamin A is intricately involved in the hypothalamic response to positive (pleasure) or negative (stress) stimuli.
(Journal of Nutritional Biochemistry, October 2014)
(Journal of Endocrinology, September 2013)

Increasing vitamin A in post-weaning diets reduces food intake and body weight and modifies gene expression in brains of male rats born to dams fed a high multivitamin diet.
LINK to ABSTRACT Vitamin A regulates hypothalamic-pituitary-adrenal axis status in LOU/C rats. 

CLINICAL UPDATE – How does vitamin D help us lose weight?

Researchers found that supplementation with vitamin D for 10 weeks limited weight gain in animals on a very high fat diet. Those supplemented with vitamin D showed an increase in lipid oxidation (fat burning) and energy expenditure (they used up more calories) which the authors say was due to a vitamin D-induced increase in the expression of genes that control metabolism.
(Journal of Nutritional Biochemistry, October 2014)

LINK to ABSTRACT Vitamin D protects against diet-induced obesity by enhancing fatty acid oxidation.

CLINICAL UPDATE – Is B12 deficiency common in thyroid conditions?

The presence of thyroid antibodies (anti-thyroglobulin and anti-thyroperoxidase) were measured in 380 men and women – half had thyroid autoimmunity (n=190) and half were age and sex matched controls with no thyroid antibodies present (n=190). A significant number of the thyroid autoimmune patients had deficiencies in either haemoglobin, iron or B12 as well as higher homocysteine than the healthy controls. However, researchers noted that although deficiencies were more prevalent in those with thyroid antibodies, most still were diagnosed as normal thyroid (TSH in normal range of 1-4½ μIU/mL) and not yet clinically hypo- or hyperthyroid, suggesting that abnormal B12, iron or homocysteine levels may precede overt thyroid disease.
(Journal of Formosan Medical Association, March 2014)

LINK to ABSTRACT Hemoglobin, iron, and vitamin B12 deficiencies and high blood homocysteine levels in patients with anti-thyroid auto-antibodies.

CLINICAL UPDATE – Why this mineral deficiency should be considered in some neurological cases

Although copper deficiency is conventionally thought of being caused by several distinct reasons – bariatric surgery, excess ingestion of zinc, or severe malabsorption for example – this report of two cases reveal that copper deficiency may be more common than previously thought, even when an attributable cause remains unidentified.  

This report on two patients who presented with ataxia (loss of muscle coordination) revealed a diagnosis of copper deficiency myelopathy (spinal cord disease). Upon supplementation, neurological symptoms improved significantly. The authors emphasize that blood copper levels should be measured in any myelopathy case, especially since this disease is progressive and copper supplementation, when deficiency exists, may “prevent irreversible neurological damage.”
(Journal of Spinal Cord Medicine, October 2014)

 Copper deficiency myelopathy: a report of two cases. 

CLINICAL UPDATE – New research concludes vitamin E and selenium provide no benefit for cataract prevention

This new study conflicts with research published earlier in 2014 stating vitamin E and selenium supplements reduced the risk of age-related cataract by 9%. In this study, 11,267 men, who had been participating in the large SELECT study (Selenium and Vitamin E Cancer Prevention Trial) were evaluated for cataract formation in a 5½ year follow up. In this cohort of apparently healthy men, “long-term daily supplementation with selenium and/or vitamin E is unlikely to have a large beneficial effect on age-related cataract,” confirming the notion that blind supplementation may not be as effective as targeted repletion of specific micronutrient deficiencies.
(Journal of American Medical Association Ophthalmology, September 2014)

 Age-Related Cataract in Men in the Selenium and Vitamin E Cancer Prevention Trial Eye Endpoints Study: A Randomized Clinical Trial.

CLINICAL UPDATE – Can vitamin D increase testosterone in women?

In a study performed at a fertility clinic on 73 healthy, non-obese women with no history of infertility, researchers measured blood levels of vitamin D, steroid hormones (DHEA, testosterone), sex hormone binding globulin and several metabolic markers for insulin resistance or dyslipidemia. They found that higher vitamin D levels were correlated to higher total and free testosterone levels in these women, but vitamin D levels did not correlate with DHEA or other steroid hormones. In addition, when vitamin D levels were above 13 ng/mL – a level commonly accepted as deficient – the correlation between vitamin D and testosterone was more pronounced, leading the authors to conclude that “vitamin D may increase fertility through modulation of androgen activity.”
(Journal of Clinical Endocrinology and Metabolism, July 2014)

 Association between sex steroids, ovarian reserve, and vitamin D levels in healthy non-obese women.