I've been amazed that her first set of teeth is so strong,' says the dietician and journalist Jane Clarke, author of Yummy! Every Parent's Nutrition Bible, when I ask about the health of her three-year-old daughter, Maya. 'She has the most beautiful smile. In the summer in Italy she goes really dark, and all you can see is those gleaming white teeth - and she's tall for her age.'

In 2004, when Clarke first held her adopted daughter at an orphanage in India, it was a different story. 'I knew from the moment I took off her clothes that she had rickets,' she says. 'Her limbs were horribly thin. It's a deficiency in vitamin D, which helps the body absorb calcium and, if you suffer from a lack of calcium, you get weak bones and then you have the classic pigeon chest and bandy legs.'

It's a common sight in Indian orphanages, where babies are fed a gruel of milky rice instead of breast milk or vitamin-enriched formula. 'Outside the orphanages, you do see children with rickets,' says Clarke, 'but it's worse in institutionalised children. Our bodies metabolise vitamin D mostly from exposure of the skin to sunlight but babies in orphanages are kept indoors and seldom see the sun.'

Once she knew about her daughter's condition, there was little Clarke could do about it. The formalities of adoption meant Maya had to remain in India while her adoptive mother shuttled between Mumbai and London. During the 10 months it took to complete the adoption, Clarke had to say goodbye to Maya half a dozen times. The longest she ever stayed with her was two weeks and in the intervals between visits, she knew her baby's health was getting worse.

'I tried to talk to people at the orphanage about nutrition,' she says, 'but they very much saw me as an interfering person, even though that was my profession. I tried to get Maya to have extra milk, and I even gave some money to the carer so she would keep a special eye on Maya but they just didn't see the problem.'

To Clarke, one of Britain's top nutritionists, it became increasingly clear that Maya had other problems. When she eventually brought her daughter home, in November 2004, she noticed that the formula milk she gave the 15-month-old 'went straight through her'. 'She had raging diarrhoea and crippling tummy ache, but when I had her tested for pathogens, she didn't have a stomach bug. My hunch was that she was lactose-intolerant, which is common in Asian children.'

What Maya had was a deficiency in lactase, the enzyme that breaks down lactose. 'Undigested lactose irritates the gut and results in terrible diarrhoea,' says Clarke. To compound matters, this disturbance of the intestine makes it less able to absorb nutrients including calcium. 'What you see is a general failure to thrive,' she explains, 'which is why Maya also had recurring chest infections.'

To her mother, the solution was obvious. 'I changed her diet to soya baby milk, removed dairy and noticed an improvement in two or three days. There was no diarrhoea, she didn't have tummy ache, she slept well and didn't have gripes.'

The soya baby milk remains in Maya's diet even at the age of three-and-a-half, providing calcium and vitamin D. 'I've also made a conscious effort to use nut butter, almond oil, green leafy vegetables and other sources of calcium,' says Clarke. The result? 'Structurally, her legs are fully recovered; you can only tell by her chest, which is a tiny bit indented but you wouldn't notice it on a beach in a bikini. Considering the tough start she had in life, Maya has really blossomed.'

The same could be said of her adoptive mother, who was diagnosed with endometriosis at the age of 15 and told, at only 20 years old, that she needed a hysterectomy and would never have children. 'I think my gynaecologist would be struck off now, for giving the same advice,' says Clarke, 'because I asked about harvesting some of my eggs which I'd heard was an option. She said, "No, you've just got to get used to the idea that you'll never have your own child".' For fi ve years, Clarke resisted a hysterectomy, such was her desire to be a mother. 'My endometriosis was very severe,' she says. 'I had at least a dozen operations to correct it, hormonal treatments. I was on morphine and pethidine, I had to be catheterised. It was a very unpleasant part of my life but my desire hung on, even though I knew the likelihood of getting pregnant was slim. At 25, I made a decision that I needed my life back. I surrendered at that point, I gave up my right, then had to deal with the grief and that took me a good five years.'

In her thirties, Clarke decided she was ready to adopt and embarked on the frustrating, bureaucratic process of trying to do so as a single woman. 'The person just never came along to share parenthood with,' she says, 'and I couldn't hang around for ages.' In the early days of applications and vetting, she met fierce resistance. 'One social worker needed evidence that I could be loving,' she says, 'so I sent a photo of me cradling a child - the son of some friends in Italy. He was three years old, we'd just come from the pool and I had a towel wrapped round me. We were reading a storybook and looking at each other, and it was obvious I loved him and he loved me. It was a beautiful shot, so I sent it to her.'

A few days later, the social worker phoned saying the image should not be submitted to the adoption panel. 'You haven't got any clothes on,' she said, 'and also, there's a Jeffrey Archer novel in the background. Someone on the panel might not like Jeffrey Archer, so that could count against you.' At one point, the social worker expressed a worry that Clarke's home was too tidy and minimalist and she might come across as controlling. Worse, the social worker contacted two friends asking if they suspected Clarke of having affairs with their husbands.

'It made me furious and I wanted to report her,' says Clarke, 'but I saw it not as a game exactly, but as something I had to get through. When you're on that mothering train, nothing is going to stop you. I wouldn't let her have that power.'

Because Clarke wanted to adopt a baby, not an older child, and there were few babies up for adoption in Britain, the 'mothering train' eventually took her to India. 'I have an affinity with India,' she says, recoiling when I ask whether adopting from a developing country was a charity act, a bit like Save the Children. 'I was never coming to Maya's aid,' she objects. 'I wanted to be a mum, and I wanted to be a mum to a little baby. It was for purely selfish reasons.'

Selfish they might have been, but Clarke could never have predicted how hard the journey would be. 'In the first orphanages I visited, in Calcutta, there were 200 to 300 children in each,' she says. 'The stench was huge because they were in pieces of cloth that didn't absorb anything. It was a very acrid smell.' Far worse, she says, was the clawing. 'There are 20 children pulling at your clothes, just reaching out for anything. They're so desperate for love, for touch. When I'd been to six orphanages like that, I thought I didn't have the strength to carry on.'

Nevertheless, Clarke persisted and was offered a healthy baby at the next place she visited but she received a call in her hotel room that night, saying the staff had changed their minds. With her 'obvious big heart' and mettle, Clarke would be the ideal mother for a disabled child and there were plenty of those. 'In India, when a child is labelled special needs,' she says, 'you know it is severe. This girl was aged about three but, biologically, looked 14 months.' 'From talking to carers, Clarke knew the child was HIV-positive and had hydrocephalus - water on the brain, resulting in an enlarged head, vomiting, irritability and seizures.

'I'd thought long and hard about taking on a child like that,' says Clarke. Even as a single mother who had to work, it would have been possible but tough. 'Holding this girl, I didn't think I had what it takes, and I beat myself up about it. To walk away from a child, if I'd not met Maya, I would really struggle with that.'

Depressed and disappointed with herself, Clarke saw no point in continuing but she couldn't get a flight home. 'I thought, well, I'm here, I might as well put in one more call,' she says. It led her to the orphanage where she found Maya.

Even then, it was not the textbook encounter Clarke had imagined. 'There were two babies, and I saw the other one first and she was premature - but there was no emotion there. I just held her and thought, "OK, that's number one." Then they brought Maya in and she was five months old, with eyes like big chocolate buttons, and she just smiled - and that was it. It was totally different from anything I'd felt before. I was her mum.'

Visceral it may have been, but there were cerebral reasons why she and Maya bonded: 'My great aunt was called May, and we were very close. I always said that if I ever had a little girl, I would call her May.' It's an engaging tale, but was this slender semantic connection really the reason why she fell in love with Maya? 'I think she gave off something very positive,' says Clarke, on refl ection. 'She was physically weak, but emotionally and developmentally she seemed to engage fully with life. She has always been an incredibly happy child.'

Three years on, Maya is just like any exuberant toddler - but there is one scary video she doesn't like to watch. It's the footage shot by Navin, a friend Clarke met in India, of the handover at the orphanage: the moment when Clarke looks at Maya and says, 'It's you and me together in this life'. Whenever she sees it, Maya asks for a bottle of soya milk and a cuddle for comfort. 'I always let her lead, I ask if she wants to see it, if she wants to talk about baby Maya,' says Clarke, 'because we've just started talking about it, but very much as a story. I tell her a mum went to India to find a baby, asked if she could be your mummy, and you said yes.'

More poignantly, Clarke herself was unable to watch the video for more than a year. 'To begin with, there was still a doubt over whether the authorities here would allow me to keep Maya,' she says. Watching those happy scenes was tempting fate. 'Also, I couldn't bear to remind myself how fragile Maya was.'

So fragile was she, Clarke made sure that, while still in India, a doctor, independent of the orphanage, gave an objective assessment of the little girl's health. 'It was partly the suspicious journalist in me,' says Clarke, 'having Maya checked. But also, as a mum, I wanted to have that conversation with the doctor and know Maya was all right. I didn't want to hear it secondhand.'

Satisfied with the doctor's verdict, Clarke did not look at the bundle of medical records presented to her as she left. Six months later, she did and was devastated. 'I remember sitting with a glass of wine in the study and starting to look back over her papers. There were some awful things. Like, they don't have a birth certificate, they have a "certificate of abandonment". My God, that's nice, isn't it? Then I came across a CAT scan saying Maya had a cyst on her brain.'

At this point Clarke pauses for a long time, fighting back tears. 'I just remember that horrible, heartstopping nausea,' she says, 'and I hadn't been told any of this. Apparently, she'd been admitted to hospital two months before I'd met her.'

Desperately, Clarke took Maya for an MRI scan and was told there was no cyst on her brain - and no evidence there had ever been one. 'I now know those medical records were entirely false,' claims Clarke. 'They were relating to another child, not mine, even though Maya's name was on them.'

This story, more than any other, shows how finely honed and close to the surface Clarke's maternal feelings are; her distress is just like that of any parent. The same is true when she describes nursing Maya back to health. 'I instinctively knew she wasn't ready for solids,' she says, 'even at 15 months. I needed to take her and be with her as Maya the baby, as someone who just had that suckling experience with her mum, with a bottle. She was just held, and she was loved.'

It's not unreasonable, allowing Maya the mothering she never had - even if it isn't mother's milk. 'These days, it's not just soya I give her but rice milk, oat milk, a balance of things,' says Clarke, sounding like a nutritionist again. 'She can tolerate a little bit of yoghurt and cheese now, but I ration it - and she certainly wouldn't have a cheese soufflé or a glass of cow's milk. If she's been to friends and had dairy ice-cream, that lays her out for days. She's really poorly.'

It seems like the kneejerk antidairy stance of the naturopath, but Clarke is a believer in the white stuff . 'Milk has its place,' she says, sipping a decaf latte at Melrose and Morgan, the suitably minimalist cafe and deli in Primrose Hill, north London. 'Milk has had a bad press but I don't agree with it. The soya industry, which has seen huge growth, has been funding a major PR campaign; it's been not so much "Our product is good" but "Cow's milk is awful". The number of offers that come through to expound the virtues of soya. One could earn big money.'

The limits imposed on Maya's dairy intake are because she is lactose- intolerant, not because milk is evil. 'If it's a genetic, cultural thing - and you're more likely to get it with Asian children - then my experience is that you stay lactose-intolerant for life.' However, Maya's recovery to date is a tribute to her mother's skill as a nutritionist - a conclusion Clarke rejects. 'It's not like I was setting an agenda of so many grams of this and so many grams of that,' she says. 'OK, I had knowledge of the nutrients people need, but, bizarrely, I was just being a mum.' OFM

Yummy! by Jane Clarke (Hodder Mobius, £12.99). To order a copy for £11.99 with free UK p&p go to observer. co.uk/bookshop or call 0870 836 0885

FISH FINGERS WITH OAT AND RYE CRUST

SERVES 4 CHILDREN
350g haddock or any firm white fish fillet, skinned
25g oat flakes
25g rye breadcrumbs
salt and freshly ground black pepper
1 medium egg
generous splash of olive oil
splash of pumpkin-seed oil

preheat the oven to 160°C/gas 3

Cut the fish into strips of a similar size to the well-known originals. Mix the oat flakes and breadcrumbs in a bowl, then season lightly.

Beat the egg in a wide bowl. Dip the fish fingers in the egg and then roll in the oats and crumbs until completely coated. Heat the oils in a pan and gently fry the fish fingers on each side until the coating turns golden. Transfer to a baking tray and place in the oven for 10 minutes or so, until cooked through.

These are delicious with mashed potato and steamed mixed greens.

FALAFEL BURGERS

1 x 400g tin of chickpeas, drained and rinsed
½ small onion, finely chopped
1 garlic clove, finely chopped
small handful of chopped flat-leaf parsley
small handful of chopped coriander
1 tsp ground cumin
1 tsp ground coriander
½ tsp cinnamon
2 tbs wholemeal flour plus extra for dusting
200ml sunflower oil for frying

Put the chickpeas, onion, garlic, herbs, spices and flour in a food processor and whiz until smooth. Flour your hands and shape the mixture into 10 patties.

Heat the oil in a frying pan until it is nice and hot. Fry the falafels on both sides for 2-3 minutes until golden brown and crispy. Leave them on a sheet of kitchen towel to drain.

Serve in a bun or pitta with lettuce, tomato and a dollop of hummus or home-made ketchup.

MUFFINS

MAKES 18 SMALL MUFFINS
30g very soft unsalted butter
4 tbs honey
3 eggs
40ml sunflower oil
1 tbs Good Oil (optional)
50ml milk
480g wholemeal flour
2 tsp baking powder
large handful of crunched cornflakes
2 tsp ground mixed spice
1 apple, grated
zest of ½ lemon
100g blueberries, 100g raspberries
2 ripe bananas, squashed

Preheat the oven to 180 °C/gas 4.

In a large bowl mix the butter and honey. Add the eggs and beat till smooth; add the oils. Put remaining ingredients apart from the fruit in another bowl in list order and mix . Gradually add the dry mixture to the wet, combining lightly. Add the fruit and stir.

Spoon the mixture into paper cups in a muffin tin and bake for 20 minutes until golden brown.