Apparently not as the technology is being used daily during the NIH clinical trial with participants.
Change in serum folate status [ Time Frame: Change from baseline serum folate status at day 1 ] Serum folate values will be analyzed through dried blood spot samples collected on Arrayit blood cards daily, which use linear flow chromatography to separate whole blood into erythrocyte and serum. The WHO-recommended cutoff of <10 nmol/L will be used to assess low serum folate status. Results will be reported as a concentration with higher values indicating improved serum folate status. Change in serum folate status [ Time Frame: Change from day 1 serum folate status at day 2 ] Serum folate values will be analyzed through dried blood spot samples collected on Arrayit blood cards daily, which use linear flow chromatography to separate whole blood into erythrocyte and serum. The WHO-recommended cutoff of <10 nmol/L will be used to assess low serum folate status. Results will be reported as a concentration with higher values indicating improved serum folate status. Change in serum folate status [ Time Frame: Change from day 2 serum folate status at day 3 ] Serum folate values will be analyzed through dried blood spot samples collected on Arrayit blood cards daily, which use linear flow chromatography to separate whole blood into erythrocyte and serum. The WHO-recommended cutoff of <10 nmol/L will be used to assess low serum folate status. Results will be reported as a concentration with higher values indicating improved serum folate status. Change in serum folate status [ Time Frame: Change from day 3 serum folate status at day 4 ] Serum folate values will be analyzed through dried blood spot samples collected on Arrayit blood cards daily, which use linear flow chromatography to separate whole blood into erythrocyte and serum. The WHO-recommended cutoff of <10 nmol/L will be used to assess low serum folate status. Results will be reported as a concentration with higher values indicating improved serum folate status. Change in serum folate status [ Time Frame: Change from day 4 serum folate status at day 5 ] Serum folate values will be analyzed through dried blood spot samples collected on Arrayit blood cards daily, which use linear flow chromatography to separate whole blood into erythrocyte and serum. The WHO-recommended cutoff of <10 nmol/L will be used to assess low serum folate status. Results will be reported as a concentration with higher values indicating improved serum folate status. Change in serum folate status [ Time Frame: Change from day 5 serum folate status at day 6 ] Serum folate values will be analyzed through dried blood spot samples collected on Arrayit blood cards daily, which use linear flow chromatography to separate whole blood into erythrocyte and serum. The WHO-recommended cutoff of <10 nmol/L will be used to assess low serum folate status. Results will be reported as a concentration with higher values indicating improved serum folate status. Change in serum folate status [ Time Frame: Change from day 6 serum folate status at day 7 ] Serum folate values will be analyzed through dried blood spot samples collected on Arrayit blood cards daily, which use linear flow chromatography to separate whole blood into erythrocyte and serum. The WHO-recommended cutoff of <10 nmol/L will be used to assess low serum folate status. Results will be reported as a concentration with higher values indicating improved serum folate status. Change in serum folate status [ Time Frame: Change from day 7 serum folate status at day 8 ] Serum folate values will be analyzed through dried blood spot samples collected on Arrayit blood cards daily, which use linear flow chromatography to separate whole blood into erythrocyte and serum. The WHO-recommended cutoff of <10 nmol/L will be used to assess low serum folate status. Results will be reported as a concentration with higher values indicating improved serum folate status. Change in serum folate status [ Time Frame: Change from day 8 serum folate status at day 9 ] Serum folate values will be analyzed through dried blood spot samples collected on Arrayit blood cards daily, which use linear flow chromatography to separate whole blood into erythrocyte and serum. The WHO-recommended cutoff of <10 nmol/L will be used to assess low serum folate status. Results will be reported as a concentration with higher values indicating improved serum folate status. Change in serum folate status [ Time Frame: Change from day 9 serum folate status at day 10 ] Serum folate values will be analyzed through dried blood spot samples collected on Arrayit blood cards daily, which use linear flow chromatography to separate whole blood into erythrocyte and serum. The WHO-recommended cutoff of <10 nmol/L will be used to assess low serum folate status. Results will be reported as a concentration with higher values indicating improved serum folate status. Change in serum folate status [ Time Frame: Change from day 10 serum folate status at day 11 ] Serum folate values will be analyzed through dried blood spot samples collected on Arrayit blood cards daily, which use linear flow chromatography to separate whole blood into erythrocyte and serum. The WHO-recommended cutoff of <10 nmol/L will be used to assess low serum folate status. Results will be reported as a concentration with higher values indicating improved serum folate status. Change in serum folate status [ Time Frame: Change from day 11 serum folate status at day 12 ] Serum folate values will be analyzed through dried blood spot samples collected on Arrayit blood cards daily, which use linear flow chromatography to separate whole blood into erythrocyte and serum. The WHO-recommended cutoff of <10 nmol/L will be used to assess low serum folate status. Results will be reported as a concentration with higher values indicating improved serum folate status. Change in serum folate status [ Time Frame: Change from day 12 serum folate status at day 13 ] Serum folate values will be analyzed through dried blood spot samples collected on Arrayit blood cards daily, which use linear flow chromatography to separate whole blood into erythrocyte and serum. The WHO-recommended cutoff of <10 nmol/L will be used to assess low serum folate status. Results will be reported as a concentration with higher values indicating improved serum folate status. Change in serum folate status [ Time Frame: Change from day 13 serum folate status at day 14 ] Serum folate values will be analyzed through dried blood spot samples collected on Arrayit blood cards daily, which use linear flow chromatography to separate whole blood into erythrocyte and serum. The WHO-recommended cutoff of <10 nmol/L will be used to assess low serum folate status. Results will be reported as a concentration with higher values indicating improved serum folate status. Change in serum folate status [ Time Frame: Change from day 14 serum folate status at day 15 ] Serum folate values will be analyzed through dried blood spot samples collected on Arrayit blood cards daily, which use linear flow chromatography to separate whole blood into erythrocyte and serum. The WHO-recommended cutoff of <10 nmol/L will be used to assess low serum folate status. Results will be reported as a concentration with higher values indicating improved serum folate status