Vitamin B12 deficiency tied to postural tachycardia in adolescents

By Reuters Staff

NEW YORK (Reuters Health) - A case-control study has revealed an association between postural orthostatic tachycardia syndrome (POTS) and vitamin B12 deficiency in adolescence.

Patients with POTS, syncope or chronic fatigue syndrome "should be screened for vitamin B12 deficiency," advise Dr. Taliha Oner and colleagues from Uz Children's Hospital in Izmir, Turkey, in Pediatrics online December 23.

Vitamin B12 is involved in the production of adrenaline from noradrenaline and catecholamine degradation and plays a role in myelin synthesis. The Turkish team investigated ties between vitamin B12 levels and POTS during adolescence, a time when accelerated myelin synthesis increases the vitamin B12 need.

Participants included 125 patients (50 boys and 75 girls) aged 11 years on average reporting short-term loss of consciousness and diagnosed with vasovagal syncope and 50 controls of similar age and gender distribution.

Overall, vitamin B12 levels were significantly lower in children with vasovagal syncope relative to controls (352.75 vs. 411.32; p<0.001). A low vitamin B12 level was more prevalent in children with vasovagal syncope (47.2% vs. 18%, p<0.001).

In the vasovagal syncope group, children with the POTS pattern had significantly lower vitamin B12 levels compared with children without the POTS pattern (312.60 vs. 352.75, p>0.05). Twenty-two of 35 children with POTS had low vitamin B12 compared with 59 of 125 overall (62.8% vs. 47.2%, p<0.05).

Dr. Oner and colleagues point out in their article that vitamin B12 deficiency is known to be more common in the elderly, "although there is a currently increasing prevalence among adolescents worldwide. This is due to the increased need associated with accelerated development, decreased intake related to inadequate diet (vegetarian diet, obesity) and the side effects of medications (metformin used in the treatment of obesity, oral contraceptives, and antireflux medications such as proton pump inhibitors)."

They say their observations suggest that vitamin B12 deficiency in patients with POTS "may lead to sympathetic nervous system baroreceptor dysfunction." They recommend screening for vitamin B12 deficiency in adolescents with POTS, syncope or chronic fatigue.

Dr. Oner did not respond to request for comment by press time.

SOURCE: http://bit.ly/1dtM7B3

Pediatrics 2013.

(c) Copyright Thomson Reuters 2014. Click For Restrictions - http://about.reuters.com/fulllegal.asp