B Vitamins, Child Health and the Nutrition Problem
Metabolic syndrome is a risk factor for type 2 diabetes, coronary heart disease and stroke. It is characterized by elevated blood pressure, large waist circumference, and low HDL-cholesterol levels. As societies transform and develop, the incidence of metabolic syndrome increases. For example, 40% of women and 29% of men living in Nairobi have metabolic syndrome.
People can still be malnourished, missing essential vitamins and minerals, even when they are overweight. Because metabolic syndrome is primarily a disorder of abdominal obesity, Yakub and colleagues evaluated the association between plasma homocysteine (Hcy) concentrations and any 3 indicators of 4 risk indicators (i. waist circumference and ii plasma glucose ≥ 85th percentile; iii blood pressure ≥ 90th percentile; and iv triglycerices ≥ 1.7 mmol/L and high-density lipoproteins < 0.9 mmol/L) in children living in Nepal who were born to women participating in a micronutrient supplementation trial. The mothers had participated in the intervention trial between 1999-2001. The authors randomly chose blood samples from a 1,000 children of the 2130 who had biomarker assessments. 48.2% of the children were underweight. 42% were stunted. 18.4% had hyperhomocysteinemia (> 12 µM/L) and 83% had low high-density lipoprotein cholesterol. Stewart and colleagues previously reported, using data including these children, that intrauterine exposure to folate ameliorated risk of metabolic syndrome.
High homocysteine concentrations (> 9 µM/L) have been associated with lower cognitive performance in children and young adults with epilepsy. Children with a waist circumference > 90th percentile (7.3 µM/L) are 2.4 times more likely to have increased homocysteine concentrations. When low low-density lipoprotein cholesterol concentrations are added as another inclusion factor, the risk increases 2.7 fold.
Folate and vitamin B12 are essential for normal brain development. Both folate and vitamin B12 are required to maintain normal circulating homocysteine concentrations. Relationships haven’t been consistently reported for plasma folate and vitamin B12 concentrations and cognitive performance but higher maternal folate status predicted childhood cognitive ability in 9-10 year old children born in India.
As identified by Dr Robert Heaney, the hypothesis underlying nutrition research isn’t that nutrition prevents or ameliorates a problem. Rather it is that nutrient insufficiency causes disease or dysfunction. We do not need to ask if nutrients are efficacious. We need to know ‘for what they are efficacious’ and ‘how much is needed’.
Yakub and colleagues report that a nutritionally sensitive biomarker, homocysteine, is related to child health risk. Others have linked B vitamins, or status biomarkers, with function. We need to act on Dr Heaney’s advice and adopt physiological criteria to move beyond definitions of nutrient deficiency and begin characterizing (defining) optimal nutrient status ranges.
Yakub M, Schulze KJ, Khatry SK, Stewart CP, Christian P, West Jr, KP. High plasma homocysteine increases risk of metabolic syndrome in 6 to 8 year old children in rural Nepal. 2014 Nutrients doi: 10.3390/nu6041649
Kaduka LU, Kombe Y, Kenya E, Kuria E, Bore JK, Bukania ZN, Mwangi M. Prevalence of metabolic syndrome among an urban population in Kenya. 2012 Diabetes Care doi 10.2337/dc11-0537
Stewart CP, Christian P, Schulze JK, Leclerc SC, West Jr KP, Khatry SK. Antenatal micronutrient supplementation reduces metabolic syndrome in 6- to 8-year old children in rural Nepal. 2009 J Nutr doi: 10.3945/jn.109.106666
Di Rosa G, Lenzo P, Parisi E, Neri M, Guerrera S, Nicotera A, Alibrandi A, Germano E, Caccamo D, Spano M, Tortorella G. Role of plasma homocysteine levels and MTHFR polymorphisms on IQ scores in chldren and young adults with epilepsy treated antiepileptic drugs. 2013 Epilepsy Behav doi: 10.1016/j.yebeh.2013.09.034
Perreira da Silva N, Suano de Souza FI, Pendezza AI, Fonseca FLA, Hix S, Oliviera AC, Sarni ROS, D’Almeida V. Homocysteine and cysteine levels in prepubertal children: association with waist circumference and lipid profile. 2013 Nutr doi: 10.1016/j.nut.2012.05.015
Veena SR, Krishnaveni GV, Srinivasan K, Wills AK, Muthayya S, Kurpad AV, Yajnik CS, Fall CHD. Higher maternal plasma folate but not vitamin B12 concentrations during pregnancy are associated with better cognitive scores in 9- to 10- year-old children in South India. 2010 J Nutr doi: 10.3945/jn.109.118075
Heaney RP. Design and analysis of clinical trials of nutrients: Author reply. 2014 Nutr Rev doi: 10.1111/nure.12118
Heaney RP. The nutrient problem. 2012 Nutr Rev doi: 10.1111/nure.1753-4887.2011.00469.x