Calcium

Calcium is a major mineral: the average adult is made up of just over a kilo (around 2% of total body weight). 99% of this is found in the bones and teeth, and the remainder is used for the contraction of muscles, nerve function, enzyme activity and blood clotting.

Calcium Requirements

The UK Department of Health's Reference Nutrient Intakes (the daily amount that is enough for 97% of people: similar to RDAs used previously in the UK) are as follows.¹

Vegan Sources of Calcium

Good plant sources of calcium include:

• Green leafy vegetables: spring greens, kale, broccoli, parsley.
  It is important to note that spinach is not a good source of calcium. It is high in calcium, but the calcium is bound to oxalates and therefore poorly absorbed

• Fortified foods such as soya milk

• White flour (as calcium is added by law) and white flour products

• Calcium-set tofu

• Oranges

• Ground sesame seeds (tahini)
  The calcium content is high but variable and absorption of calcium from tahini is not proven so tahini should not be relied upon as a main source

• Figs and black molasses

• Drinking hard water can provide 200mg of calcium daily, although soft water contains almost none² 

  
  

  Examples of amounts of foods providing 100mg calcium

Ensuring an adequate intake of calcium

A study in the UK of 34,696 adults, over five years, found that the vegans studied had a higher risk of bone fracture than the meat eaters, fish eaters and vegetarians studied. This appeared to be a result of their lower calcium intake no increase in risk was found in those vegans consuming at least 525 mg of calcium per day and highlights the importance of ensuring an adequate intake of calcium.⁴ Recommended intakes are given in Calcium Requirements above.

Calcium is a team player

Calcium is sometimes thought of as the 'bone-builder', but it should not be viewed in isolation. Other nutrients including vitamin D, vitamin K, protein and potassium play an important part in building bones. Exercise also helps to build bones.

Vitamin D assists with calcium absorption so it is important to ensure a supply. Expose your face and arms to the sun for approximately 15 minutes per day. If your sun exposure is limited (for example in a British Winter), or if you are dark skinned make sure that you get 10 to 20 micrograms of vitamin D2 each day from fortified food or a supplement such as VEG1 available from The Vegan Society.

Other Factors To Consider:

Salt (sodium) causes calcium loss, so opt for low-sodium salt (e.g. Losalt) and low-sodium foods.
Caffeine reduces calcium absorption so reduce your intake of caffeinated foods and drinks such as coffee and tea.
Vegetables and fruit improve calcium balance so eat plenty.
Protein stimulates bone building so it is important to ensure an adequate intake of protein, but avoid excesses. Moderate protein intake about one gram of protein per kilogram of body weight per day is probably ideal.

Further details

For more details on bone health, see please see The Vegan Society's information sheet Diet & Bone Health, or our briefing paper on Diet & Bone Health available from us for £2 (paper copy) or free by email.

For more details on the vegan diet in general see Plant Based Nutrition and Health by Stephen Walsh. This book is the most comprehensive survey of scientific research on vegan diets. It is ideal for vegans, would-be vegans and health care professionals.

References

1. Dietary Reference Values for Food Energy and Nutrients for the UK Dept of Health (1991)
2. Water in the north is generally harder than in the south. Ask your water company for their latest water quality report.
3. The Composition of Foods (6th Summary ed) McCance & Widdowson 2002 Royal Soc of Chemistry & Food Standards Agency
4. Key TJ, Appleby PN, Spencer EA, Roddam AW, Neale RE, Allen NE. (2007) Calcium, diet and fracture risk: a prospective study of 1898 incident fractures among 34 696 British women and men. Public Health Nutr. 2007; 10(11):1314-20