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From Dickensian remedy to modern dilemma
Once dismissed as a foul-tasting relic of Victorian medicine, cod liver oil is now recognized for its high vitamin D and A content. Its historical use against rickets has resurfaced in debates over whether the UK should revive food fortification to combat rising deficiency rates.
The science behind the spoonful
Extracted from codfish livers, the oil was empirically linked to lower rates of rickets long before vitamins were discovered. By 1919, researchers confirmed its role in preventing the bone disease, which can trigger seizures and heart complications. During World War II, the UK government distributed free cod liver oil to young children, alongside campaigns urging parents to include it in daily routines.
Despite its benefits, the oil's rancid taste and fishy odor made it unpopular. Sunlight, a natural source of vitamin D, proved unreliable in the UK's cloudy climate-an issue projected to worsen as winters grow 30% rainier by 2070, according to Met Office forecasts.
Fortification's rise and fall
To address deficiencies, governments turned to fortifying staples. The UK mandated vitamin D in margarine in 1940, while the U.S. added it to milk in 1933. Finland launched a voluntary fortification program in 2003, achieving near-universal industry participation.
However, UK efforts stalled in the 1950s after cases of hypercalcaemia-a condition causing kidney stones-emerged. Experts suspected vitamin D overdoses, leading to a ban on fortification, except for margarine and infant formula. The UK later discontinued margarine fortification in 2013, shifting focus to supplements, though uptake remained low.
Deficiency resurgence and modern challenges
Recent data paints a stark picture: nearly 40% of UK children and 30% of adults are vitamin D-deficient during winter months. Darker-skinned populations face higher risks, with public health nutritionist Judith Buttriss noting "almost universal" deficiency among UK South Asians.
Rickets, once rare, has surged. Hospital admissions for the disease peaked in 2011 at their highest levels in five decades. In 1991, England recorded 0.34 cases per 100,000 children under 15; by the 2000s, rates had soared.
Is fortification the answer?
Scientists now believe past hypercalcaemia cases stemmed from a genetic disorder, not excessive fortified foods. The UK's Scientific Advisory Committee on Nutrition is reevaluating fortification policies, suggesting a potential shift.
While multiple factors contribute to rickets' resurgence, the debate underscores a question: Could a modern version of cod liver oil-or fortified foods-help reverse the trend?
