Here are some links covering the discussion about mandatory B12 fortification of food:

Folic Acid and Vitamin B12 Fortification of Flour: A Global Basic Food Security Requirement

Folic acid is an essential water soluble B vitamin which has been used for decades
in the prevention of folate deficiency anemia of pregnancy. In 1991, folic acid taken
prior to the start of pregnancy was shown unequivocally to prevent spina bifida and
anencephaly—two of the most serious and common birth (neural tube) defects.

Soon governments recommended that women of reproductive age consume folic
acid daily to prevent these birth defects. Because compliance was low and since
more than half of pregnancies are unplanned, the United States Food and Drug
Administration mandated in 1998 that all enriched l our be fortified with folic acid
at a concentration estimated to give the average woman an intake of 100 micrograms
of folic acid a day. Canada and Chile followed with similar requirements for folic
acid fortification of wheat l our. Now there is mandatory fortification in more than
50 countries globally.

Where fortification has been implemented and studied, it has led to dramatic
increases in serum folate concentrations, reduction in neural tube defects, folate
deficiency anemia, as well as the reduction in homocysteine concentrations and
stroke mortality with no known risk. Australia implemented mandatory folic acid
fortification in 2009. To date, no country in Europe has implemented mandatory
folic acid fortification of l our, although it has been recommended by the UK Food
Safety Authority. This review discusses the vital importance of mandatory l our
fortification with folic acid and vitamin B12, for public health food security and as
a challenge to the New Public Health in Europe and globally.
When will we eliminate folic acid-preventable spina bifida?
Mandatory vitamin B12 fortification of enriched grain products is long overdue in the United States and Canada. Fortification would help provide the 2.4 mug of synthetic vitamin B12 that the US Institute of Medicine recommends for all persons 50 years and older. The findings of Ray and colleagues in this issue suggest that B12 may also help to prevent neural tube defects. If recommendations for B12 fortification were followed, it is possible that cases of spina bifida and anencephaly would be prevented. Two hundred twenty thousand children each year acquire folic acid-preventable spina bifida because many governments, including all in Europe, have yet to implement mandatory folic acid fortification. Fortification with folic acid and vitamin B12 is safe and should be implemented in all countries.
And, from yesterdays news:
Mandatory enrichment food legislation coming
Dar es Salaam. The government is finalising establishment of regulations that will make food fortification by large scale producers mandatory, a World Bank nutrition specialist has said.However, millers say implementation of the proposed arrangement could be difficult, unless the government move to exempt taxes related to the ingredients or importation of any fortified food.

The World Bank has supported the national food fortification programme for the past 2-3 years. “Funding for various activities is underway… national regulations have been finalised and are just awaiting for gazetting by the minister for Health and Social Welfare, then fortification will become mandatory for all large scale industries,” said Ms Janneke Jorgensen of the World Bank.

She was speaking on Thursday at a meeting on Progress Towards Food Fortification in Tanzania, attended by different stakeholders and the development community in Dar es Salaam yesterday.

If the legislation comes into force, Tanzania will be the first country in the East Africa region to have mandatory food fortification.The process simply means addition of folic acid, iron, zinc and vitamin B12 into wheat and maize flour during milling and putting vitamin A during production of cooking oil for the purpose of preventing nutrition disorder among the population.