The results demonstrate that the program did not significantly improve B12 status in comparison with the control group. B12 deficiency is relatively common among older people and is associated with metabolic, haematological, cognitive, and neuroconduction problems . In a study recently published by our group, we found a B12 deficit of 12% using the cut-off of <148 mpol/L and 25.4% using the cut-off of <221 pmol/L . Allen obtained similar results in an American population  and Loikas in a Turkish population .
The possible causes of B12 deficiency in the older adult population fall into two main categories: a) gastric atrophy associated with aging, which impedes the absorption of B12 from foods due to a lack of acid [29, 30], along with decreased levels of intrinsic factor, which is an essential element for B12 absorption in the ileum; and b) low intake of B12 containing animal products . Preliminary data from an on-going study  suggest that the intake of B12 from foods in older adults is on average 5.4 μg/day. The average intake of foods delivered by PACAM is 25 g/day of powdered milk drink and 3 portions/week of dried soup. Therefore the vitamin B12 intake provided by the programme is about 0.7 μg/day, thus resulting in an intake of 6.1 μg/day. Therefore, considering the recommended daily requirements (2.4 μg/day) for older people it would seem that the deficiency observed in Chile is due primarily to gastric atrophy.
One of the great challenges in nutrition program design at a population level is defining the best course of action for addressing B12 values below the acceptable limit (148 pmol/L).
Studies of a Latino population residing in the United States have demonstrated normalised plasma B12 levels after adding fortified foods or supplements (F/S) >500 μg/day to the diet. In addition, it has been found that F/S in the crystalline form of the vitamin is the most effective, as it is well absorbed by individuals with and without gastric mucosa atrophy .
A possible weakness of this study was that the intake of PACAM products was not specifically quantitated; however, considering that the study was an effectiveness evaluation, no assessment of PACAM intake beyond the usual controls of the program was considered. Another potential weakness was not establishing the usual intake of B12, but Chilean data suggest that the average intake of B12 in older adults is above the daily-recommended allowance.
After the intervention, the folate levels decreased in both groups, showing that PACAM fortification with folic acid has little or no effect. Taking into account that the absorption of folic acid is not influenced by age, and bread consumption in Chile is very high in all groups of age, it is possible to postulate that this decrease is due to a reduction in the amount of folic acid in wheat flour during the years when the CENEX study was carried out, as described by Castillo .
In Chile, the National Program of Complementary Feeding for the Elderly over the age of 70 provides 45.8% of the daily-recommended intake of B12. Our findings show that this amount does not ensure that this population maintains adequate levels of B12. Therefore, it is important to address a number of questions regarding the nutritional programs implemented in our country: First, we should evaluate the true amount of micronutrients provided by the foods included in these programs. Second, we should evaluate the effectiveness of fortifying PACAM products with crystalline B12 in quantities greater than the RDA. Finally, we should review existing B12 recommendations for this age group.
There is an international consensus on the need to target B12 in particular in nutrition interventions for older adults if foods are universally fortified with folic acid .
Chile has a long and successful experience in nutrition intervention programs; however, the country’s changing demographic, epidemiologic and nutritional profile requires a constant surveillance of the nutritional programs, carrying out periodic evaluations of the programs’ impact on the target population.
The high burden of illness associated with chronic nutrition-related diseases on a global and national level significantly affects national health budgets. This makes it even more important to evaluate the interventions and identify the most cost-effective course of action , without losing sight of the fact that nutrition and physical activity are fundamental for maintaining an active, healthy, and autonomous lifestyle and high quality of life for older adults.