Health: Supplement warnings ‘do more harm than good’

Research studies suggesting potential health threats arising from vitamin and mineral consumption could be doing more harm than good, Natural Products NZ says.

Natural Products NZ  represents companies selling supplements and other non-pharmaceutical products. Its chief executive, Alison Quesnel, says “unbalanced coverage of one-off studies suggesting potential problems could backfire by scaring consumers off taking supplements that benefit their health.”

Recent media coverage has highlighted the potential pros and cons of using vitamin D and a study that raises questions about fish oil.

“Although occasional studies question fish oil’s benefits, the vast majority have shown that fish oil in supplements and/or food can help to lower high levels of triglycerides (unhealthy blood fats),” she says.

Many studies also show vitamin D, when combined with calcium, helps to maintain good bone health and protect against osteoporosis (see below).

Ms Quesnel says The Lancet, the UK-based medical journal, recently recommended large clinical studies be undertaken to assess vitamin D’s effects on other health conditions such as heart diseases, diabetes, cancer, dementia and inflammatory diseases.

Vitamin and mineral deficiencies can have severe and potentially life-threatening effects, which is why supplements such as folate (to prevent spina bifida) and iodine (to prevent conditions associated with poor thyroid function) are routinely added to food products, she says.

Articles about the potential risks associated with particular nutritional supplements are often based on selected excerpts from studies that do not actually conclude the extent to which the supplement affects health conditions, she says.

“In reality, many of these studies simply demonstrate the need for more research.”

Vitamin D deficiency increasing
Vitamin D deficiency is becoming increasingly common and the Ministry of Health believes that around 5% adults are deficient and a further 27% have below the recommended vitamin D blood level.

People with low vitamin D risk developing a range of conditions, including rickets (bone deformation), weak bones and heart disorders.

Vitamin D can be boosted through sensible sun exposure or by choosing foods that contain it, for example: oily fish (salmon, tuna, sardines, eel and warehou), milk and milk products, eggs and liver.

Some foods may also have vitamin D added, including: margarine and fat spreads, some reduced-fat dairy products (milk, dried milk and yogurt), plant-based dairy substitutes (soy drinks) and liquid meal replacements.
– Natural Products NZ