Tag Archives: Supplements

Calcium

You do not need to drink milk to get enough calcium. You will not make your bones stronger by drinking milk.

If you don’t believe these statements, don’t worry, you are not alone. Seventy years of marketing has convinced most health professionals that dairy foods, or a high-calcium substitute, are essential for human health. This is a rather narrow nutritional view when one considers that cow’s milk is only consumed by a minority of the world’s population, and for a relatively short period of human history. Most of the world’s population, including the majority of those of Asian or African descent, are lactose intolerant and suffer abdominal pain and diarrhoea if they drink milk.

While it is true that dairy foods are rich in calcium and that calcium is an essential nutrient for bone health, increased dairy consumption is not associated with stronger bones. In fact, a large Swedish study (Michaelsson et al 2014) found that higher milk consumption was associated with a higher rate of hip fractures (as well as a higher mortality rate). The higher prevalence of osteoporosis in countries that consume more dairy foods suggests that dairy products are not an effective preventative strategy.

You don’t need to reach for calcium fortified foods to get enough calcium on a whole foods plant-based diet

Like other minerals, calcium comes from the ground. Plants absorb it and animals in turn eat plants. Cows get their calcium from the grass. We can obtain all our calcium needs from whole plant foods, many of which have moderately high calcium levels. Some vegetables have a higher “nutrient density” for calcium than dairy foods (see Nutrient Density page). Interestingly, calcium is better absorbed from vegetables than milk, over 50% vs 32%. Many whole plant foods are rich in calcium – a cup of chopped kale, for example, provides as much absorbable calcium as a cup of milk.

Calcium content of food

Dairy (and ‘dairy alternatives’) has its own food group in the Australian Dietary Guidelines but this is no longer the case for the Canadian dietary guidelines. A liberal interpretation of ‘dairy alternatives’ might include beans, greens and other high calcium whole plant foods. A plant-based ‘milk’ with a similar calcium content to cow’s milk is not necessary. Indeed, it has been argued that a more appropriate comparator for plant ‘milks’ is human breast milk which has only a third of the calcium content of cow’s milk.

The recommended daily intake for calcium in Australia is extraordinarily high, up to 1300mg per day, a level which few people reach. It remains to be seen whether this will be revised in future guidelines given the evidence that high dietary calcium intakes are not protective against osteoporosis (Bolland et al 2015). The World Health Organization (2004) notes that calcium needs are increased by high intakes of animal protein and sodium. Dietary animal protein increases urinary loss of calcium and at very high protein intakes it can be difficult to absorb enough calcium to offset losses. WHO suggests a lower calcium requirement where animal protein intake is lower, and if sodium intakes were also lower as in developing countries then the calcium requirement would be even lower, e.g. 450mg (WHO 2004, p. 82).

A study of older Chinese men and women on a “plant-based diet” in the Journal of Bone and Mineral Research (Fang et al. 2016) suggested there was an optimal range for calcium intake, and that both very low and very high intakes were associated with higher fracture rates. It may surprise you to learn that this range of optimal intakes was 250-650mg/day for women and 275-780mg/day for men. In the discussion the authors suggest that policy makers rethink the dietary reference intakes for calcium and the policy of milk promotion in developing countries. These results provide evidence that older Chinese men and women eating a plant-based diet may require half as much calcium than their Western counterparts for fracture prevention – approximately 400mg per day. A typical whole foods plant based diet provides at least 500mg of calcium per day and more often 700-800g without having to reach for calcium fortified foods.

Calcium supplements are not effective in preventing osteoporosis and clinical trials have observed an increase in kidney stones and cardiovascular events. Australian doctors are now being urged to consider the risks and benefits before recommending calcium tablets. Osteoporosis is not caused by calcium deficiency and it is not prevented by calcium supplements. See Osteoporosis page. Getting enough calcium on a dairy-free diet of whole plant foods is a non-issue and there is no need to consume plant ‘milks’ for calcium.

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Page substantially revised 9 December 2019
Page last updated 30 December 2019
Resources updated 8 March 2024

Vitamins and Minerals

Specific vitamins, minerals and other nutrients:

Most vitamin and mineral supplements are of no benefit and some may be harmful. With few exceptions we recommend that you get your vitamins, minerals, fibre and other phytonutrients from minimally processed plant foods. The supplements that may be required are related to modern living conditions rather than any inherent deficiency of a plant based diet. Clean food and water and safe food handling, whilst preventing disease, may remove most of the bacteria-derived vitamin B12 from our food supply. Indoor living can deprive us of the UV rays that are required for vitamin D synthesis. Many people take supplements as an insurance policy against dietary inadequacy or to detoxify the effects of too many rich foods. Unfortunately, supplements neither emulate the benefits of nutrients from plants, nor detoxify the harmful effects of excess animal protein, fats and processed foods.

Whole food is complex (see ‘Whole’ by T Colin Campbell in resources below). Our understanding of it is very basic. We know which nutrients are absolutely essential for life and the approximate amounts required. We have identified only a small number of the thousands of other biologically active substances in plants (known as phytochemicals or phytonutrients). We know little of the interactions between these various nutrients and phytonutrients. Often a high intake of a particular nutrient from food is associated with a health benefit, such as less cancer, but when we give them as supplements rather than as whole foods the benefit may be absent or reversed, increasing cancer risk.

There are some medical conditions in which vitamin supplements can be used as a pharmaceutical. Several of the B group vitamins can assist in reducing high homocysteine levels and this has been shown to reduce the progression of the early stages of dementia (see VITACOG study). The dietary approach would be to remove the cause of the elevated homocysteine levels by reducing animal protein consumption. While on the topic of dementia, Dr Neal Barnard recommends a vitamin B12 supplement and advises against taking supplements that contain minerals such as iron, copper and zinc as high levels of these may damage the brain.

No particular food has exclusive ownership of any particular nutrient. You do not need dairy foods for calcium, red meat for iron or fish for omega 3 oils. You do not even need to know which foods are the “best” sources of any particular nutrient. You just need to eat enough calories of whole grains, legumes, vegetables and fruits to maintain a healthy weight. And if you wish to tweak your plant-based diet to include more omega-3s, iodine, resistant starch or any other nutrient or phytochemical then we suggest that you bypass the supplements and just find some whole plant foods rich in the particular phytonutrient and make them a regular part of your diet.

See video: Dr. John McDougall Medical Message: Vitamin Supplements

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Last updated 11 April 2015