The vitamins in mushrooms

The vitamins in mushrooms

The mushroom has more protein than most vegetables and a carbohydrate content similar to zucchini and tomatoes (see Table 1). Cholesterol-free and with virtually no fat, the mushroom is a very low kilojoule food. A serve of mushrooms is 100g, which is equivalent to three button mushrooms or one flat mushroom.

Table 1. Macronutrient profile/100g fresh mushrooms

Nutrient
Protein (g)	3.3
Carbohydrate (g)	0.3
Fat (g)	0.3
Cholesterol (mg)	0
Fibre (g)	1.5
Energy kJ (kcal)	103 (24)

Source: NUTTAB 2006 Online

The mushroom is also an abundant source of essential nutrients (see Table 2), surprising many health professionals with its nutrient diversity and density. A serve of mushrooms provide over 20% of the Recommended Dietary Intakes (RDI), or daily needs, for each of the B vitamins riboflavin, niacin, pantothenic acid, biotin, and the minerals selenium and copper, while also providing an appreciable amount of folate and bioactive compounds. No vegetable can match the nutrient profile of the mushroom.

Table 2. B vitamins, minerals & other important compounds in mushrooms

Nutrient	Amount /100g	%RDI	Amounts in other foods/100g	Amounts in common vegetables/100g
Riboflavin (B2) mg	0.37	30	Milk (2% fat) 0.18	Parsley 0.33; broccoli 0.2; spinach 0.2;
Niacin equiv (B3) mg	3.7	23	Mince beef 4.2	Green peas 3.4; avocado 1.9; parsley 1.5
Pantothenic acid mg	1.15	20	Chicken thigh 0.92	Avocado 0.9; broccoli 0.5; sweetcorn 0.5
Biotin mcg	8.9	30	Milk (2% fat) 3.7	Broccoli 9.8; cauliflower 5.7; avocado 5.0
Folate mg	18	4.5	Spinach 120	Asparagus 114, Broccoli 49
Selenium mcg	15.4	22	Tuna tinned 80	Sweetcorn 1.3; celery 1.8
Copper mcg	342	20	Peanuts 564	Avocado 271; green peas 147
Potassium mg	310	10	Banana 345	Spinach 570; tomato 200; zucchini 150; cucumber 100
Phosporus (mg)	110	10	Roast lamb 325	Green beans 42; carrot 35; capsicum 20

• mg = milligrams; mcg = micrograms
• RDI = Recommended Dietary Intake (covers the daily needs of a nutrient)
• source: NUTTAB 2006 Online 

About one third of your riboflavin (vitamin B2) needs can be obtained from a serve of mushrooms. Riboflavin is involved in the release of energy from carbohydrate, protein and fat. It is uncommon to see mushrooms listed as a source of niacin (vitamin B3), yet it can provide a quarter of our daily needs. Niacin can also be made in the body from the amino acid tryptophan. The role of niacin in the body is closely related to that of riboflavin as it is involved in cell respiration and the metabolism of carbohydrate, fat and protein.

Pantothenic acid is involved in more than 100 different steps in making neurotransmitters, hormones and haemoglobin, while biotin is also involved in the normal metabolism including the production of glucose. Both vitamins work primarily as co-enzymes, compounds that allow enzymes to function properly. A serve of mushrooms will provide around 20% of your daily needs of these two vitamins.

Vitamin B12

There has long been speculation about whether or not mushrooms provide vitamin B12, a vitamin normally associated with animal foods. In 1987, the Australian Government Analytical Laboratories found appreciable amounts of B12 in mushrooms.

Based on this analysis, the mushroom industry then included B12 as a nutrient in their promotional material and advertising. The B12 level was disputed by some nutrition professionals who believed that only animal sources can provide B12, while others wanted to know whether the B12 claimed to be found was bio-available.

In early 2009, researchers at the University of Western Sydney completed ground-breaking research on the B12 content of button mushrooms. Their detailed experiments on mushrooms of all sizes and stages of growth from around Australia conclusively proved that:

A. Mushrooms do have B12 present. It is on both the surface of the mushroom and in the flesh of the mushroom. The majority of B12 is in the surface of the cup of the mushroom.

B. The B12 present is bio-available, in exactly the same form as B12 in beef liver and fish.

C. The average amount of B12 in mushrooms is still to be calculated, but is not likely to be more than 5% of the RDI. However, that level may be an important amount for a vegan over a lifetime.

The results of the vitamin B12 study will be published in a peer reviewed scientific journal. We shall give you the full details when this occurs.

Vitamin D

Vitamin D has sparked a lot of interest this century, as adequate vitamin D has been linked to a number of benefits beyond healthy bones and the prevention of rickets and osteoporosis, such as a decreased risk of heart disease, type 2 diabetes, hypertension and colorectal cancer (Lee 2008, Wang 2008, Dobnig 2008). It is now felt that a review of the dietary needs for vitamin D is required (Yetley 2009).

The adult RDI for vitamin D ranges from 5-15 mcg, with more being needed by older people. Compare that to the typical vitamin D dietary intake of 2-3 mcg daily by adults (Nowson 2002). The common dietary form of vitamin D in Australia is cholecalciferol (vitamin D3) available from table margarine, canned fish and eggs (Shrapnel 2006). Both vitamin D2 and D3 are offered as supplemental vitamin D in Australia.

Mushrooms too, are a source of vitamin D. It is quite natural for ergocalciferol (vitamin D2) to be found in mushrooms. Wild mushrooms, through the action of sunlight, convert their abundant ergosterol to ergocalciferol. Once consumed, this vitamin D2 is converted to D3. Wild mushrooms in Europe commonly have 10-60 mcg vitamin D/100g (Mattila 1994, Mattila 2002, Teichmann 2007).

There is a small amount of vitamin D in cultivated mushrooms as they don’t need light to grow. Farmers generally don’t subject their mushrooms to light other than during growing operations and harvesting. However, if these mushrooms are exposed to a short burst of ultraviolet light they generate in excess of the daily recommended intake for vitamin D.

In fact, Vitamin D-enhanced mushrooms are now available in supermarkets in the US, providing at least the daily allowance of vitamin D in a single serve. Farmers mimic nature by passing the mushrooms under a UV light with the same spectrum as sunlight. A few seconds is all it takes for the D2 conversion process to be activated.

Following research at the University if Western Sydney (Koyyalamudi 2009) showing that UV light boosts the vitamin D levels in mushrooms, the Australian mushroom industry is currently refining the US technique to their growing system so consumers in Australia can also have D-enhanced mushrooms in the near future.

The vitamin D in mushrooms is easy to absorb (Outila 1999; Jasinghe 2005; Koyyalamudi 2009). There is at least an 85% retention of vitamin D in wild mushrooms after frying for five minutes (Mattila 1999). Furthermore, there is very little loss of vitamin D2 when the mushrooms are refrigerated for eight days (Koyyalamudi 2009) or even three months (Mattila 1999). This means that mushrooms can be a very useful source of vitamin D to the consumer, whether eaten raw or cooked.

Vitamin D-enhanced mushrooms will become a simple and delicious way for Australians to get 100% of their daily vitamin D needs, especially if they are unable to get adequate sun exposure.

Source : mushroomsforlife.net