Informing National Fortification Policy

Challenge

Namibia’s Food and Nutrition Security Policy and Implementation Action Plan (2019–2024) committed the government to mandatory fortification of staple foods as a strategy to address micronutrient deficiencies. But before setting fortification standards, policymakers needed answers to a series of interconnected questions: which foods do Namibian households actually consume, in what quantities, and through which supply chains? How does consumption vary across the country’s 14 regions and demographic groups? And what is the baseline for nutrients — like iodine — where fortification is already underway?

The Iodine Global Network contracted A3DI for a multi-phase analytical programme built around the 2015–16 National Household Income and Expenditure Survey (NHIES), a 12-month nationally representative survey with seven-day food diary entries linked to household demographics and income. The raw microdata had not been analysed at the level of detail needed for fortification vehicle selection, dosage setting, or supply-chain targeting.

Approach

A3DI built a modular analysis system in Python across 15+ Jupyter notebooks, supported by a custom analytics module for weighted survey calculations (weighted means, weighted medians, and a generalised disaggregation function). The work proceeded in four interconnected phases.

Grain production and consumption baseline. The initial phase categorised food diary items into grain types (wheat, mahangu/pearl millet, maize, sorghum) and tracked whether households sourced grain from own production or market purchase — a critical distinction, since only commercially processed grain can be fortified. Results were disaggregated by region, urban/rural classification, income level, language, and household head demographics, then validated against Ministry of Agriculture administrative data.

Daily intake for seven fortification vehicles. Building on the baseline, A3DI calculated grams per capita per day (g/c/d) estimates at national and regional levels for each candidate vehicle: wheat, maize, mahangu, salt, milk, oil, and sugar. Household-level prevalence — the share of households consuming each vehicle at all — was computed alongside mean intake to distinguish between low average consumption and narrow reach.

Food Composition Table harmonisation. Four FCTs (West African 2012, Kenyan, USDA SR24, and South African 2017) were standardised into a single 199-item dataset covering calcium, iron, zinc, folate, and vitamins A through E. The South African table required PDF extraction using Camelot before it could be integrated. The harmonised dataset fed into FAO’s ADePT-Food Security Module for micronutrient adequacy modelling.

Historical salt iodization trends. Three rounds of DHS data (2000, 2006, 2013) were analysed to track salt iodization status over 13 years, disaggregated by region, urban/rural residence, and education level. This provided the historical baseline for a nutrient where Namibia already had a fortification programme in place.

Result

The analysis revealed dramatic regional variation in consumption of candidate fortification vehicles. Wheat intake ranged from 30 to 292 g/c/d across regions; mahangu from 4 to 452 g/c/d; maize from 67 to 338 g/c/d. Own-production consumption exceeded 45% for certain grains in specific regions, meaning a substantial share of household grain intake would not be reached by mandatory commercial fortification alone.

Salt consumption averaged 5.4 g/c/d nationally (median 4.9), ranging from 2.8 to 7.5 g/c/d across regions — essential data for setting fortification dosage levels that deliver adequate micronutrients without exceeding safe limits. The DHS trend analysis showed how iodization coverage had evolved, identifying regions where historical progress had stalled.

The harmonised Food Composition Table gave government and IGN stakeholders a standardised, locally relevant nutrient database for modelling the impact of different fortification scenarios. All work was delivered as reproducible Jupyter notebooks with Excel workbook outputs, enabling stakeholders to explore results directly and update the analysis as new survey data becomes available.